Technical Service-Electronic product solution company-Electronic and electrical product development-Bluetooth design-S

Technical Service

07-13

2023

Product Show—SN8F5701

SN8F5701 is compatible with MCS-51 instruction set eight-bit microcontrollers, and under the same execution frequency standard, its efficiency can reach up to 12.1 times of the original 8051. At the same time, the operating voltage range (1.8 V to 5.5 V) and operating temperature (-40°C to 85°C) are expanded through advanced semiconductor technology, allowing the product to operate at high speed in various applications.In this microcontroller, built-in 4 KB ROM, 256 bytes IRAM. In addition, the microcontroller also has a 12-bit high-precision ADC, a set of PWM generators, two sets of 16-bit counters (timers) and a UART communication interface to meet the needs of consumer electronics, home control, and brushless motor control. occasion.Shenzhen Zuchuang Microelectronics is the agent of Songhan in mainland China. It sells Songhan microcontrollers and voice ICs, and can provide technical support for Songhan's solutions. It can also directly develop and design electronic products for customers. It has rich hardware development With experience in program design, it can help customers quickly develop products and put them on sale as soon as possible.SN8F5701.pdf
07-13

2023

Product Show—SNC27P020

SNC27P020 is a single-channel speech synthesis IC with 12-bit PWM direct-drive circuit, which integrates one input port and 8 I/O ports into a 4-bit microcontroller. Through the programming of the microcontroller in the SNC27P020, various applications of the user, including the synthesis of voice parts, the setting of key triggers, output control and other logic functions, can be easily realized. Note: SNC27P020 has no LVD function.feature of productWorking voltage: 2.1V~5.1V·System Clock: 2.304 MHz-1.5%·Duration: 20 seconds @6KHz ·RAM size: 128*4 bitsmaximum value. 64K*12 bit program size ·I/O Ports: - Input Port P9.0 Shared Reset Pin
07-12

2023

Product Show—SN8P2501D

SN8P2501D is an 8-bit microcontroller with RISC-like system, featuring high performance and low power consumption. 1T (one instruction cycle is one clock cycle) structure, 16MIPS computing power. In addition, the high EFT performance makes it suitable for use in high-noise industrial environments.SN8P2501D has first-class IC structure, including 1K-word program memory (OTP ROM), 48-byte data memory (RAM), two 8-bit timer counters (T0, TC0), a watchdog timer, and 3 interrupts Source (T0, TC0, INT0), one channel PWM output (PWM0), one channel buzzer output (BZ0) and 4 layers of stack registers.SN8P2501D also provides 4 different oscillator modes for the system as the system clock: including high/low speed crystal oscillator/ceramic resonator and cheap RC oscillator. In addition, SN8P2501D also includes an internal 16MHz RC oscillator as the system clock and a programmable internal low-frequency RC oscillator as the system clock in low-speed mode.Shenzhen Zuchuang Microelectronics is the first-level agent of Sonic, which can sell Sonic single-chip microcomputers and voice ICs in mainland China, and can provide technical support for Sonic solutions, and can also directly develop and design electronic products for customers. Experience in hardware development and program design can help customers quickly develop products and sell them on the market as soon as possible.SN8P2501D.pdf
07-06

2023

Principle of DC Boost Circuit

DC boost technology is an engineering technology that converts non-adjustable DC voltage into adjustable or fixed DC voltage. One method is to use the energy storage function of the inductor and the filtering function of the capacitor to boost the voltage; the other method is to use high frequency Oscillation generates low-voltage pulses, which are then boosted to a predetermined voltage by a pulse transformer, and then pulse rectification technology is applied to obtain high-voltage direct current. The DC step-up process is realized by a conversion circuit that controls electric energy by means of switching regulation, that is, a DC-DC converter. The core component of the DC-DC converter is a switching converter composed of a crystal diode, an energy storage device (or transformer), a capacitor and an inductor. Its output circuit rectifies the current through a low-pass filter composed of capacitors. Realize the output of high voltage direct current.The continuous update and improvement of DC boost technology has greatly affected the evolution of DC-DC converter topology. High power density, high efficiency, high performance, high reliability, low cost, and small size are the development directions of DC-DC converters. At present, DC boost technology has been widely used in battery-powered portable devices, high-power DC transmission technology, photovoltaic power plants and other fields, and has a good application prospect.1. Principle and analysis of DC boost circuitAs a DC-DC converter that converts DC into another fixed voltage or adjustable voltage, the DC boost circuit is used in DC drive systems, charging and storage circuits, switching power supplies, power electronic conversion devices and various electrical equipment. common application. Subsequently, various conversion circuits such as step-down circuits, buck-boost circuits, and composite circuits have appeared. According to the topology of the circuit, it is mainly divided into isolated and non-isolated circuits.1. Non-isolated circuitThe non-isolated topology includes BUCK circuit, BOOST circuit, CUK circuit, SEPIC circuit, etc. Among them, the BUCK circuit is a DC step-down circuit, and the BOOST step-up circuit is the most widely used, and it is also the basis of the latter two circuits. Therefore, this section focuses on the principle and characteristics of the BOOST boost circuit.The basic topology of the BOOST boost circuit is shown in the figure below. The switch in the actual circuit is generally an IGBT element (insulated gate bipolar transistor, which is composed of a BIT (bipolar transistor) and a MOS (insulated gate field effect transistor). Composite fully-controlled voltage-driven power semiconductor devices, which have both the advantages of high input impedance of MOSFET and low conduction voltage drop of GTK) or thyristor components, and the corresponding control signals are pulses based on PWM technology generator to provide.According to the analysis of the closing and opening of the switch s according to the analog circuit, combined with the basic knowledge of circuit theory, the output voltage can be deduced.To sum up, the boosting process of the BOOST circuit is the energy transfer process of the inductor. When charging, the inductor absorbs energy; when discharging, the inductor releases energy. If the capacitance is large enough, a continuous current can be maintained during the discharge of the output. If this on-off process is repeated continuously. A voltage higher than the input voltage can be obtained across the capacitor.The diode in the circuit is mainly used for isolation, that is, when the switch is closed, the voltage of the anode of the diode is lower than the voltage of the cathode, and the diode is cut off at this time, so that the energy storage process of the inductor does not affect the normal power supply of the output capacitor to the load: because in When the switch is turned off, the two superimposed energies supply power to the load through the diode. At this time, the diode is forward-conducting. It is required that the forward voltage drop should be as small as possible, so that more energy can be supplied to the load terminal as much as possible.The non-isolated DC-DC topology is relatively simple, the number of components required for the circuit is small, and it is easy to design and control, but it is also limited by the input-to-output voltage ratio, which cannot be applied to occasions with a large voltage conversion ratio, nor can it achieve Electrical isolation requirements, these topologies are suitable for low power equipment.2. Isolated circuitThe isolated topology mainly includes "flyback circuit", "forward circuit", "push-pull circuit", "half bridge circuit", "full bridge circuit" and related circuits derived from these basic circuits .The basic working process of this circuit is as follows: high-frequency oscillation generates low-voltage pulses—pulse transformer step-up to a predetermined voltage value—pulse rectification to obtain high-voltage direct current.Among them, the push-pull DC boost circuit is more widely used. At the same time, after the push-pull circuit is bridge rectified or full-wave rectified, the voltage ripple and current ripple of the output voltage are very small, so only a small energy storage is required. filter capacitor or energy storage filter inductor, an output voltage with very small voltage ripple and current ripple can be obtained. Therefore, the push-pull circuit is a switching power supply with very good output voltage characteristics.The main disadvantage of the push-pull circuit is that when the system works for a long time or often runs at high power, the circuit is prone to unbalanced magnetic flux, that is, the phenomenon of magnetic bias, and it is easy to burn out the shutdown tube and related devices. Another disadvantage of the push-pull circuit is that the switch tube of the circuit has a large turn-off withstand voltage value. Compared with other circuits, its withstand voltage must be greater than twice the working voltage. Therefore, push-pull circuits are rarely used at high voltage input.2. Application of DC boost circuitDC boost technology meets the demand for higher DC voltage during operation of equipment using DC power sources such as batteries, and has been widely used in mobile phones, pagers and other wireless communication equipment, camera flashes, portable security detectors, electric mosquito swatters, etc. application. At the same time, the development of high-power DC transmission technology, photovoltaic power generation technology, and uninterruptible power supply (UPS) technology is also inseparable from the application of DC boost technology.1. Application in LED driverIn the application circuits of electronic products such as mobile phones and digital cameras, it is usually necessary to drive the LED of the flash module or the LED of the display backlight through a boost circuit to adjust the brightness of the LED. The circuit for driving LED can generally be divided into two types: parallel drive and series drive. Parallel drive adopts the principle of capacitive charge pump voltage multiplication, and all LED loads are connected in series; series drive adopts the principle of inductive DC boost conversion (Boost circuit) to increase the total voltage of the system to meet the requirements of a single LED in series. The rated voltage demand of the load. The series drive circuit booster device is small in size, high in efficiency, and takes up less space, so it is widely used in mobile phones, digital cameras, PDA handheld devices, MP3 players, GPS receivers and other devices.The inductive DC boost conversion of series LEDs applies the Boost circuit boost principle, and the boost device MP1518 chip of Monolithic Power Systems (MPS) is well applied to mobile phones and other equipment. In addition, under the condition of a certain input voltage, the voltage across the drive LED is related to the duty cycle of the signal. The greater the duty cycle of the signal, the greater the output voltage, and the greater the brightness of the LED. In practical applications, a PWM wave is often added to the enable pin EN, and the brightness of the LED is adjusted by changing the duty cycle of the PM W wave.2. Application in solar photovoltaic power generation systemThe power generation principle of a solar cell is to utilize the photoelectric effect caused when it is incident on a semiconductor. The basic characteristics of photovoltaic cells are similar to diodes, which are completely different from traditional power generation methods. There is no rotating part of the rotor and no electromagnetic interaction is used. Therefore, the current generated by it is direct current. The photovoltaic power generation system mainly includes solar panels, chargers, batteries, controllers, DC boost circuits, inverters, etc.A typical photovoltaic power generation system consists of four parts: photovoltaic cell array, energy storage system, inverter, and DC control system. Among them, the electric energy emitted by single photovoltaic cells is very small, which is direct current. In order to meet actual needs and obtain a large enough power generation, it is necessary to connect single photovoltaic cells to form a battery pack, and then form a solar photovoltaic array by the battery pack. During the transmission and exchange of electric energy from the photovoltaic array to the energy storage unit, and then to your transformer unit, to maintain the efficient and safe operation of the system, a DC control system is required to adjust, protect and control the entire process.When the light is strong, the low-voltage direct current of the solar cell is directly provided to the DC boost circuit, and the battery is charged and stored through the charger; when the light is weak, the output power of the solar cell cannot meet the requirements of photovoltaic power generation. At this time, as an energy storage device The storage battery provides low-voltage DC power for the DC boost circuit, ensuring the continuity and stability of the photovoltaic power generation system. The DC boost circuit raises the low-voltage DC to 330V high-voltage DC, and then can get 50Hz/220V AC through the inverter. The output AC voltage and current are fed back to the controller through the detection circuit, and the controller can realize closed-loop control.3. Application in photomultiplier tubePhotomultiplier tubes are widely used in various photoelectric detection instruments. Similarly, in the field of biomedical engineering, photomultiplier tubes play an irreplaceable role in photoelectric imaging detection and treatment instruments (such as PET). The power supply of the early photomultiplier tubes was boosted by a power frequency transformer and then rectified by voltage doubling. This kind of power supply has a large volume and poor effect. At present, the high-voltage power supply of the photomultiplier tube adopts the DC converter method, which is smaller in size and higher in efficiency than the rectification scheme after boosting the power frequency transformer, and has a good application prospect.The input DC voltage is +12 V, the output voltage is adjustable, and the typical output voltage is +1200 V. Its main components are low-voltage DC power supply, PWM control circuit, power switch tube, high-frequency transformer, voltage doubler rectifier circuit, filter circuit and sampling feedback circuit. The +12 V DC input voltage provides working power for the control circuit and the transformer; the output signal of the PWM control circuit drives the power transistor to provide a low-voltage high-frequency square wave for the high-frequency transformer; the AC output signal of the high-frequency transformer is further obtained by a voltage doubler rectifier circuit Boost and rectify, output DC high-voltage signal: the high-voltage output signal is further filtered after passing through the filter circuit, effectively reducing the output ripple coefficient; the output voltage feedback circuit provides a voltage feedback signal for the PWM control circuit, through the pulse modulator The reference voltage of the error amplifier is compared to control the output pulse duty cycle of the pulse modulator, so as to achieve the purpose of regulating the output voltage.Summary of boost circuit technologyThis article describes the principles and applications of two main DC boost circuits. The BOOST circuit achieves the purpose of boosting the voltage through the switch tube and inductor energy storage. It is relatively simple, has high power density, low current, and uses a non-isolated topology; and because of this, it is itself a source of electromagnetic interference that may cause dysfunction of surrounding electronic equipment. The circuit using transformer boosting, represented by the push-pull DC boost circuit, adopts an isolated topology, and can further boost the voltage through the turns ratio and the subsequent voltage doubler rectifier circuit, which is more suitable for the input voltage. Low voltage, high voltage ratio, and isolation is required. The two have a wide range of applications based on their own characteristics. In the application circuits of electronic products such as mobile phones and digital cameras, it is usually necessary to drive the LED of the flash module or the LED of the display backlight through a boost circuit to adjust the brightness of the LED. In the photovoltaic cell, the low-voltage direct current converted from light by the direct current step-up circuit is charged and stored in the battery through the charger. Another example is that in the photomultiplier tubes widely used in various photoelectric detection instruments, the high-voltage power supply for the high-voltage electric field between the plates adopts the DC converter method, which is smaller than the rectification scheme after boosting the power frequency transformer. ,efficient.The above is the principle and application of the DC boost circuit introduced by Shenzhen Zuchuang Microelectronics Co., Ltd. If you have software and hardware function development needs for smart electronic products, you can rest assured to entrust them to us. We have rich experience in customized development of electronic products, and can evaluate the development cycle and IC price as soon as possible, and can also calculate PCBA quotations. We are a number of chip agents at home and abroad, including MCU, voice IC, Bluetooth IC and modules, wifi modules. We have hardware design and software development capabilities. Covering circuit design, PCB design, single-chip microcomputer development, software custom development, APP custom development, WeChat official account development, voice recognition technology, Bluetooth wifi development, etc. It can also undertake the research and development of smart electronic products, the design of household appliances, the development of beauty equipment, the development of Internet of Things applications, the design of smart home solutions, the development of TWS solutions, the development of Bluetooth audio, the development of children's toys, and the development of electronic education products.
07-05

2023

Product Show—AC6936D

While ensuring stable performance, AC693N also has the characteristics of low power consumption. Because it is a highly integrated single-chip solution, the chip package is smaller and the user experience is naturally better. Its working voltage is: AC6933C (2.2V~5.5V), AC6936D (2.2V~4.2V).AC6933C and AC6936D are the same chip source. AC6933C is a specially sealed IC model that focuses on the BLE low-end market. AC69336D is mainly used in the Bluetooth headset market. The advantages are low power consumption and good sound quality. The charging compartment is automatically turned on, and TWS can realize manual switching between master and slave.Product application: TWS earphones, central control earphones, unilateral earphones, wearable devices, BLE/SPP transparent transmission moduleBluetooth version: Bluetooth audio 5.0+BLE5.0;1. Solution advantages of Jerry AC6936DJerry's AC6936D hard-core Bluetooth 5.1 chip supports Bluetooth wireless stereo high-speed transmission of lossless audio. AC6936D has a built-in intelligent lossless noise reduction algorithm, which realizes binaural high-definition calls and seamless master-slave switching.Jerry AC6936D adopts industry-leading chip production technology. The power consumption of Bluetooth ear music playback is only 6mA. Combined with high-quality polymer lithium battery, it can play music for 6-8 hours and stand by for 100 hours. Excellent customer experience.AC6936D realizes intelligent power on and off, automatic connection of headphones out of the warehouse, and automatic shutdown when placed in the charging chamber, making it more intelligent and convenient to use. Support intelligent voice AI, connect to voice assistant, and realize intelligent voice interaction function.2. Features of Jerry AC6936D(1) Master-slave switching, intelligent charging compartment;(2) Ultra-small package, high integration, few peripheral materials;(3) Lossless music, HIFI sound quality, ultra-low power consumption; the reference theoretical power consumption is AC693N (6~8mA), the specific power consumption is related to the functions of the product, and the above power consumption is for reference only.(4) MESH networking, convenient configuration tools;(5) Bilateral call, AI intelligence;(6) Gensor knocking; analog digital silicon mark;(7) Intelligent connection, OTA upgrade, built-in charging management, constant current and constant voltage;AC6936D.pdf
07-01

2023

Product Show—AC6901A

Representative models of Jerry's AC69N series are: AC6901A (LQFP48), AC6905A (SSOP24). Since the launch of the AC690N series in December 2016, the low-end Bluetooth market has been highly recognized. According to statistics, the total shipments in 2017 exceeded 400 million units, and the audio market share exceeded 50%. Support BLE4.2+classic bluetooth dual-mode.Application areas: Bluetooth story machine, pure Bluetooth speaker, card-plug Bluetooth speaker, large speaker with pull rod, car Bluetooth, AI smart speaker, point reading pen (voice emission, serial code, magic sound function).1. Brief introduction of Jerry Bluetooth chip AC6901AAC6901A is a single-chip Bluetooth solution launched by Jerry in December 2016. It is packaged in LQFP48 and supports MP3 and WAV. At the same time, it also supports the decoding of lossless formats FLAC and APE, and 24-bit DAC output. It integrates Bluetooth + plug-in card + radio, and the version of Bluetooth is 2.1+EDR. It can be said that this chip is a powerful chip that is the best choice for developing a plug-in card Bluetooth speaker.Jerry’s AC690N series chips are all in one wafer, but they are packaged in different ways according to different needs, that is to say, the AC6901A (LQFP48) and AC6905A (SSOP24) packaged wafers in the AC690N series are the same, AC6901A The chip can be programmed repeatedly. Its operating voltage range is: 3.3V~5.5V, and the theoretical power consumption is 20~25mA. The specific power consumption is related to the functions of the product. This power consumption value is for reference only.2. Chip features of Jerry Bluetooth AC6901A1. High integration: built-in MCU+2.1EDR+BLE4.2+NFC+FM+FLASH; easy production, easy patch, easy maintenance, easy stocking, easy upgrade;2. Rich decoding formats: support MP3, WAV, WMA, FLAC, APE and other decoding formats;3. The sound quality is low noise and the call effect is good: the signal-to-noise ratio of the DAC reaches more than 90dB;4. Powerful main control functions: 32-bit RISC MCU, the system can run up to 200MHz, flexible Bluetooth background, rich peripheral interfaces, support USB, SDIO, UART, SPI, IIC, PWM, IIS, LCD controller, NFC, RTC, TIMER , MIC, ADC, DAC, AUX, touch buttons, recording, reverberation and other functions; card solutions with display, and up to 32 available GPIOs, which can form many functions. Support remote control function. Support USB device, TF card, FM, AUX, Bluetooth. The buttons support 10 stably, and the previous song and the next song can be expanded at will.5. Support TWS: bilateral call;6. Small package: small package LQFP48, pins out on all sides, the smallest package is QFN32 4*4;AC6901A 芯片规格书.pdf
06-26

2023

NFC Bluetooth Quick Connect

Research on Realizing Bluetooth Fast Connection Using NFC TechnologyIn recent years, as people have put forward higher requirements for the intelligent experience of automobiles, the development of automotive electronics has accelerated, further promoting the application of electronics, communication and other technologies in the automotive field. Bluetooth communication technology has always been the main wireless technology for vehicle communication. The traditional car bluetooth relies on the mobile phone to manually connect with the car bluetooth. The steps are cumbersome, and there are often situations such as being stuck or failing to connect, which greatly reduces the interactive experience. In recent years, Near Field Communication (NFC) technology has been greatly developed and matured. NFC technology is an interconnection technology jointly researched and developed by Philips and Sony for non-contact identification. As a standardized short-distance high-frequency wireless communication technology, the working frequency of NFC technology is l3.56MHz, and the communication distance is 5-10cm.Compared with other radio frequency identification (RFID) technologies, NFC has the characteristics of extremely short reading and writing distances. However, this seemingly disadvantage itself limits the monitoring and attack of potential hackers, and has higher security. If the characteristics of these two communication technologies can be cleverly used, it will bring better user experience and communication security, and improve the competitiveness of automotive electronics in the market. Therefore, applying NFC technology to the field of mobile payment has become a research hotspot.1. NFC technical solution1.1 NFC working modeNFC works in three modes: card emulation mode, reader-writer mode, and peer-to-peer communication mode.(1) Card emulation mode. NFC is equivalent to a non-contact IC card in the card simulation mode. It writes some information into a mobile device with an NFC device. After the information is read by an external device, it returns instructions to guide the next operation. Therefore, the NFC mobile device can be used for activities such as mobile payment without changing existing devices.(2) Reader mode. NFC is equivalent to a tag that can be read and written in the reader-writer mode, such as electronic posters, scenic spot maps, etc., and the advertising data and map data are written into the NFC tag, and the handheld NFC mobile device can read it to obtain the required information. Information.(3) Point-to-point mode. In point-to-point mode, NFC can realize data transmission and communication between two mobile devices with NFC. For example, two devices exchange business cards or help the connection between two Bluetooth devices, by exchanging the data necessary for Bluetooth connection, to avoid the tedious operation process of Bluetooth connection.1.2 NFC communication mode(1) Active communication mode. In the active communication mode of NFC, the initiator and receiver alternately generate radio frequency fields. The initiator communicates at a preset transmission speed, and the receiver also needs to respond with load modulation data at the same transmission speed.(2) Passive communication mode. In NFC passive communication mode, the sender generates a radio frequency field. This radio frequency field excites the receiver device. At this point, the sender starts communicating at the agreed speed, and the receiver responds with load-modulated data at the same speed.1.3 NFC architectureNFC technology is based on non-contact technology and is compatible with non-contact Ic card standard (ISO 14443 protocol) wireless communication technology. This technology has become a formal international standard, the ISO 18092 standard (NFC IP-1). The architecture of NFC technology includes the physical layer, data exchange layer, and application layer from bottom to top. The lowest physical layer standards include ISO 14443, ISO 18092, and ISO 15693, as shown in Figure 1. The data exchange layer mainly includes protocol standards for NFC devices to exchange data in three modes.2. Android-based NFC terminalDue to the expansion of the demand for NFC in the field of electronic consumption, the voice of combining NFC technology with mobile phones has gradually increased. This combination not only enables the application of smart phones in the field of electronic consumption, but also will invisibly increase the importance of such smart devices in life. Smart mobile devices with NFC can replace credit cards and electronic smart cards when applied to contactless payment. In addition, the smart mobile device can also be used in real life such as identification, social networking, and bus cards. The NFC terminal is basically similar to the ordinary Android device terminal, but the NFC module is added to realize its functions. System hardware block diagram shown in Figure 2. The NFC module has a communication interface and a control interface. It communicates with the baseband chip through the UART, and realizes the start-up control of the NFC module through the GPIO of the baseband chip. The NFC chip is connected to the SIM card of the mobile phone through the SWP interface, and the SIM card of the mobile phone is used as a security guarantee for the NFC module, storing user information in the SIM card, and the NFC module can read the information through the SWP interface.The baseband chip is the basic module of a standard mobile phone, which can send, receive and process data communication, and provides interfaces with memory modules, power modules, SD cards, WiFi modules, Bluetooth modules, NFC modules, SIM cards, etc. The NFC module mainly includes a power module, a radio frequency module, and a baseband processor module. The power supply module supplies power to the NFC module and controls the power supply; the radio frequency module modulates the baseband information and transmits it, and receives the radio frequency information returned by demodulation; the baseband processor module is responsible for encoding the information and decoding the received data information.2.1NFC module is connected with the baseband chipThe baseband chip realizes complete control of the NFC module, and the UART communication only needs to pass through two transmission lines to complete the sending and receiving of data. Since the UART interface design method is more flexible and convenient, the transmission rate can also be defined by software. Therefore, using the UART interface to connect the NFC module to the baseband chip facilitates the control of the NFC module by the baseband chip without hindering other functions of the mobile phone.2.2 NFC module is connected with SIM cardAs an important security module, the SIM card is connected to the NFC module through the SWP interface, and the NFC reads the pre-stored security information in the SIM card through the SWP interface. Connect with the NFC controller through the C pin (ie swp) on the SIM card to realize full-duplex communication. The RST, CLK, and I/O of the SIM card are directly connected to the baseband chip, and the SWP is connected to the NFC module.3. Combination of NFC and Bluetooth technologyBased on NFC and Bluetooth technology, the main function of vehicle-mounted applications is to use the characteristics of safety, convenience and speed of NFC short-distance communication to replace complex operations such as searching for devices and pairing in the process of Bluetooth transmission and connection. On the basis of NFC, the encryption mechanism that comes with the Bluetooth specification is not used. Before transmitting data, the sender device first sends the Bluetooth MAC address to the receiver device through NFC touch to avoid the generation of a PIN code; After pairing, send data to the other party using Bluetooth non-secure mode.3.1 NFC and Bluetooth hardware connectionThe Bluetooth terminal can quickly pair and connect through NFC, mainly based on the simple security pairing protocol (bluetooth secure simple pairing, SSP) proposed by the NFC alliance. Since the SSP protocol enables out-of-frequency pairing, the NFC link can complete information exchange and participate in the process of out-of-frequency pairing. Therefore, the pairing of the Bluetooth terminal no longer requires cumbersome search connections and PIN code authentication.Due to the establishment of the Bluetooth Advanced Audio Broadcasting Protocol (A2DP) in the current Android 4.0 version, it is more convenient to use NFC to accelerate the Bluetooth pairing process. The pairing process includes the following two steps: first, read the NFC data exchange format (NFC data exchange format, NDEF) record from the external memory, and then perform connection pairing between two Bluetooth terminals.3.2 Fast connection based on NFC car BluetoothThe advantages and disadvantages of NFC technology and Bluetooth technology complement each other, which can accelerate the connection speed of Bluetooth in the car. The simple secure pairing (securesimpleprotocol, ssP) protocol in the Bluetooth technology used by the connection terminal is an NFC-based Bluetooth connection protocol recommended by the SIG and the NFC Forum in 2011. When the SSP protocol uses out-of-frequency pairing, the NFC link can participate in out-of-frequency pairing and complete information exchange. Therefore, the pairing of the Bluetooth terminal does not need to search for connection and PIN code authentication, which can greatly shorten the connection time. It mainly includes the following steps.(1) The Bluetooth OOB data packet specified in the SSP protocol is generated by the processing chip. The data packet contains 2 bytes of OOB data length, 6 bytes of Bluetooth device address and OOB operation data. Among them, the OOB operation data includes the Bluetooth module name, HASHC code, R code, UUID (the globally unique identity code of each service and its attributes in Bluetooth, and the UUID of the Bluetooth connection process service is used here) and the device level code.(2) After the data is generated, the processor packages the OOB data packet into a complete NDEF record according to the NFC data exchange format (NDEF), and sends it by the NFC module of the handheld terminal A.(3) After the transmission is completed, the handheld terminal A controls the listen function of the Bluetooth Socket to enter the listening waiting state.(4) The Bluetooth module of the handheld terminal receives the connection request of the vehicle terminal through the accept function, registers the program UUID with the system, and starts the thread for sending data. In order to strengthen system security, the elliptic curve encryption algorithm is added to the connection pairing process. Using this encryption algorithm, the handheld terminal transmits the ECC key to the receiving device through NFC touch before transmitting OOB data. After the vehicle-mounted terminal decrypts correctly according to the received ECC key, it analyzes the OOB information contained in the record of the handheld terminal, and according to the Bluetooth name, address and unique UUID data in the OOB information, through the connect function in the Bluetooth Socket, it sends data to the handheld terminal. Apply for a connection request. The transmitted data can be encrypted with a key, and then the encrypted information is sent to the other party using the Bluetooth non-secure mode. After receiving it, the receiver decrypts and restores the data, thus completing the data transmission between the two devices. This will greatly improve the security of data transmission while increasing the speed of Bluetooth connection.SummarizeThis paper implements the NFC function based on Android, and proposes a solution to apply it to automotive electronics, and compares the connection time-consuming analysis results of its pairing with traditional Bluetooth through testing. Adding the NFC function module to the Android system is an increasingly strong demand for modern intelligent devices. And then apply it to automotive electronics, whether it is a car phone, Bluetooth audio or electronic key, it simplifies people's life, improves safety during driving, and provides users with a good experience.The above is the method of using NFC technology to realize Bluetooth fast connection introduced by Shenzhen Zuchuang Microelectronics Co., Ltd. for you. If you have Bluetooth product design and development needs, you can trust us. We have rich experience in custom development of smart electronic products. We can evaluate the development cycle and IC price as soon as possible, and can also calculate the PCBA quotation. We are a number of chip agents at home and abroad: Songhan, Yingguang, Jieli, Ankai, Quanzhi, realtek, with MCU, voice IC, BLE Bluetooth IC, dual-mode Bluetooth module, wifi module. We have hardware design and software development capabilities. Covering circuit design, PCB design, single-chip microcomputer development, software custom development, APP custom development, WeChat official account development, voice recognition technology, Bluetooth development, wifi technology, etc. It can also undertake the research and development of smart electronic products, the design of household appliances, the development of beauty equipment, the development of Internet of Things applications, the design of smart home solutions, the development of TWS earphones, the development of Bluetooth earphone speakers, the development of children's toys, and the research and development of electronic education products.
06-25

2023

Bluetooth Security Vulnerabilities and Attacks

Analysis of Security Vulnerabilities and Attack Methods of Bluetooth TechnologyIn current network applications, the Internet of Things has ubiquitous requirements for item diversity, low cost, low speed, and short distance. Such requirements are mainly realized through low-speed network protocols such as Bluetooth. Bluetooth is an open standard for short-distance communication, which uses embedded chips to realize wireless connections with a communication distance between 10m and 100m. The design goal of Bluetooth is to enable personal devices produced by various manufacturers to more easily realize low-speed data transmission and cross-operation through this network protocol through a unified short-range wireless connection standard. Bluetooth technology has the characteristics of low cost, low power consumption, small module size, and easy integration, which is very suitable for application in new IoT mobile devices.1. The security system of Bluetooth technology1.1 Four-level security mode(1) Security mode 1: Security mode l does not have any security mechanism, does not initiate a security program, and has no security functions such as verification and encryption. In this mode, the device runs faster and consumes less, but the data is easily attacked during transmission. . Bluetooth V2.0 and earlier versions support this mode.(2) Security mode 2: Security mode 2 is a mandatory eye layer security mode, and the security program can only be initiated when the logical channel of the channel is established. In this mode, security policies such as authentication requirements, authentication requirements, and encryption requirements for data transmission determine whether to generate an instruction to initiate a security program. All current Bluetooth versions support this mode, and its main purpose is to make it compatible with versions before V2.0.(3) Security mode 3: Security mode 3 is a link layer security mechanism. In this mode, the Bluetooth device must initiate a security procedure before the channel physical link is established. This mode supports functions such as authentication and encryption. Only versions above V2.0 support security mode 3, so this mechanism is less compatible and flexible than security mode 2.(4) Security Mode 4: This mode is similar to Security Mode 2. It is a service-level security mechanism. The ECDH algorithm is used in the link key generation link, which is more secure than the previous three modes and the device pairing process is somewhat different. Simplified, man-in-the-middle attacks and passive eavesdropping can be prevented to some extent. When connecting a device, it is the same as security mode 3 to first determine whether to initiate a security program. If necessary, check whether the key is available. If the key is available, use the simple direct pairing method of SSP to connect through the authentication and encryption process.1.2 Key Management(1) Link key: The link key is a 128b random number, which is activated by the pseudo-random number RAND, personal identification code PIN, and device address through the E21 or E22 stream cipher algorithm. The initial key and combined key are generated through the initialization process and are used as temporary link keys to be discarded after the authentication between devices is completed. The master key can be used by devices to broadcast encrypted information in the piconet, and the master key will replace the original link key when sending broadcast information. After the unit key is generated, it will be saved in the Bluetooth device and will be directly applied to the link communication.(2) Encryption key: The authenticated Bluetooth device can use the encryption key to encrypt the transmitted data during communication. The key is generated by the symmetric encryption algorithm E3 algorithm, the word length is 128b, and is generated by the pseudo-random number RAND, the encryption offset COF generated in the authentication process, and the current link key K. Bluetooth adopts the method of group encryption, the encryption key and other parameters (device address of the main device, random number, Bluetooth clock parameters) generate a binary key stream through the E0 algorithm to encrypt and decrypt the transmitted data.1.3 AuthenticationThe purpose of authentication is to authenticate the identity of the device, and at the same time give feedback on whether the parameter transfer is successful. It can be either a one-way process or a mutual authentication, but both need to generate a link key in advance. The device address of the authenticated device, the random number generated by the authenticated main device, and the link key are all involved, thereby generating a response message and an authentication encryption offset value. The former is passed to the main device for verification. If the same Then the authentication is successful. If the authentication fails, a certain length of waiting time is required before authentication can be performed again. The authentication process is shown in Figure 3.2. Known Bluetooth Security Vulnerabilities2.1 Frequency hopping clock: Bluetooth transmission uses adaptive frequency hopping technology as the spread spectrum method, so the running counter in the frequency hopping system contains a 28-bit frequency hopping clock with a frequency of 3.2kHz, so that the control instructions are strictly in accordance with clock synchronization, information sending and receiving timing and Frequency hopping control thus reduces transmission interference and errors. However, attackers often interfere with the work of the frequency hopping command generator and frequency synthesizer by attacking the frequency hopping clock, so that the Bluetooth devices cannot communicate normally, and use the strong wave penetration and propagation width of the electromagnetic pulse to eavesdrop on the communication Parameters related to content and frequency hopping.2.2 PIN code problem: The personal identification number (PIN) in the key control diagram is four digits, which is the only trusted source for generating the encryption key and the link key. When two Bluetooth devices are connected, the user needs to separate them in the device Enter the same PIN code to pair. Due to the short PIN code, the number of keys in the key space of the encryption key and the link key is limited to 10 orders of magnitude, and if the user uses an overly simple PIN code (such as continuous same characters), long-term Bluetooth devices that do not change the PIN code or use a fixed built-in PIN code are more vulnerable to attack. Therefore, in versions after V2.1, the length of the PIN code is increased to 16 bits, which increases the key space and improves the security of the Bluetooth device connection authentication process, and it will not be caused by using too long data. The string brings inconvenience to communication.2.3 Link key spoofing: The link key used in the communication process is based on the fixed unit key in the device, while other information in the encryption process is public, so there are large loopholes. For example, when device A communicates with different devices, it uses its own unit key as the link key. An attacker uses device C that has communicated with A to obtain this unit key, and can forge another link key that has communicated with A. The device address of device B calculates the link key, and pretends to be B to pass A's authentication, and B pretends to be c as well.2.4 Encrypted key stream repetition: The encrypted key stream is generated by the E0 algorithm, and the generation sources include the main device clock, link key, etc. During a particular encrypted connection, only the clock of the master device is changed. If the device continues to be used for more than 23I3 hours, the clock value will start repeating, resulting in a keystream identical to that used in the previous connection. The repetition of the key stream is easy to be exploited by the attacker as a loophole, so as to obtain the initial plaintext of the transmitted content.2.5 Authentication process/Password in simple and secure pairing: In addition to using the personal identification code PIN for pairing, the Bluetooth standard has added a simple and secure pairing SSP (SecureSimplePairing, SSP) method starting from version V2.1. The SSP method is more convenient than the previous PIN code pairing. Unlike PIN code pairing, which requires two paired devices with input modules to enter the pairing password at the same time, SSP only needs two paired devices with output modules to confirm whether it is displayed on the screen. Just the same random number. Establish a Bluetooth physical connection through device search, generate a static SSP password, and establish a connection in four steps of authentication. However, this association model does not provide protection against man-in-the-middle attacks, and static SSP passwords are easily broken by man-in-the-middle attacks.3. Security Threats of Bluetooth TechnologyThe attack threats against Bluetooth can be roughly divided into two types, one is an attack applicable to different wireless networks, and the other is a specific attack against Bluetooth.3.1 Denial of service attack: The principle of denial of service attack (DOS) is to continuously send connection requests to the attacked target in a short period of time, so that the attacked target cannot establish a normal connection with other devices. The Bluetooth logical link control and adaptation protocol stipulates that the higher-level protocol of the Bluetooth device can receive and send 64KB data packets, similar to ping data packets. For this feature, the attacker can send a large number of ping data packets to occupy the Bluetooth interface, so that The bluetooth interface cannot be used normally, and the bluetooth is always in a high-frequency working state, which drains the battery of the device. The flow chart of DoS attack is shown in Figure 4.3.2 Man-in-the-middle attack: The attacker between two devices intercepts the data sent by one party and then forwards it to the other party, so that the content of the communication between the two parties can be obtained without affecting the communication between the two parties. It is a widely used in wireless networks. attack method. The Bluetooth Low Energy technology (BluetoothLowEnergy, BLE) of the Bluetooth 4.0 version has security measures to prevent man-in-the-middle attacks at the beginning of the design, but in the product stage, considering factors such as product power consumption and cost, this aspect has not received enough attention, and it is still easy. being attacked. The most common is to forge BLE communication with a Bluetooth attack device combined with hardware and software to carry out man-in-the-middle attacks. A schematic diagram of a man-in-the-middle attack is shown in Figure 5.3.3 Vulnerability eavesdropping: Bluetooth eavesdropping can be realized by attacking Bluetooth vulnerabilities. The OBEX (ObjectExchange) protocol in Bluetooth, that is, the object exchange protocol, did not mandate the use of authorization in early Bluetooth product specifications, so attackers can take advantage of this vulnerability Link to the attacked mobile phone without being prompted by the attacked mobile phone, obtain permission to add, delete, and modify various multimedia files and SMS call records in the mobile phone, and even make and answer calls through mobile phone commands. The instruction codes with these attack functions are written by hackers as mobile phone software, which can be downloaded on the Internet. Ordinary people usually use a graphical interface to operate, and some counterfeit mobile phones even have this function. After successfully pairing with other mobile phones, they can obtain the operation authority of the other mobile phone. However, with the continuous improvement of Bluetooth technology, attacks against early Bluetooth vulnerabilities are now becoming less and less common.3.4 Replay attack: The principle of replay attack is to monitor or forge the authentication credentials of the communication between the two parties, and then send it back to the attacked party for authentication after processing. There are 79 channels in the Bluetooth transmission process, and the attacker can attack by monitoring the channel, calculating the frequency hopping sequence, and playing back the IZI command of the authorized device. A protocol to prevent replay attacks has been added to the V4.2 standard.3.5 Pairing eavesdropping: The default 4-digit PIN code of Bluetooth V2.0 and earlier versions is easy to be cracked by violence, because the arrangement and combination of low-digit numbers is very limited, and the LE pairing of Bluetooth V4.0 is the same. As long as the attacker listens to enough data frames, he can determine the key through brute force cracking and other methods, simulate the communication party, and achieve the attack purpose.3.6 Location attack: Each Bluetooth device has a unique 6-byte serial number as the device address. Since this serial identification does not change during use, it is easy to leak the location information of the device. The attacker can obtain the geographical location of the attacked device according to the Bluetooth FM connection mechanism and paging mechanism, device identifier and other communication parameters.3.7 Simple pairing mode attack: The SSP secure simple pairing connection method stipulated by Bluetooth V2.0 is not safe, because it uses a static password and cannot prevent man-in-the-middle attacks, and once the attacker obtains the password, it can be used within a period of time Make persistent attacks.SummarizeWith the rapid promotion of Internet of Things technology in manufacturing, agriculture, and household equipment, the application prospects of Bluetooth cannot be underestimated, but it is also facing greater challenges. Therefore, we look forward to further implementing the necessary security strategies in the future design of the Bluetooth standard. At the same time, when using Bluetooth devices for transmission, we should also increase the security awareness of the use of Bluetooth devices and try to use the strongest security mode.The above is the analysis of security vulnerabilities and attack methods of Bluetooth technology introduced by Shenzhen Zuchuang Microelectronics Co., Ltd. for you. If you have Bluetooth product design and development needs, you can trust us. We have rich experience in custom development of smart electronic products. We can evaluate the development cycle and IC price as soon as possible, and can also calculate the PCBA quotation. We are a number of chip agents at home and abroad: Songhan, Yingguang, Jieli, Ankai, Quanzhi, realtek, with MCU, voice IC, BLE Bluetooth IC, dual-mode Bluetooth module, wifi module. We have hardware design and software development capabilities. Covering circuit design, PCB design, single-chip microcomputer development, software custom development, APP custom development, WeChat official account development, voice recognition technology, Bluetooth development, wifi technology, etc. It can also undertake the research and development of smart electronic products, the design of household appliances, the development of beauty equipment, the development of Internet of Things applications, the design of smart home solutions, the development of TWS earphones, the development of Bluetooth earphone speakers, the development of children's toys, and the research and development of electronic education products.
06-24

2023

Bluetooth protocol stack architecture

1. Bluetooth core protocol architectureThe Bluetooth core protocol includes Baseband Protocol (Baseband), Link Management Protocol (LMP), Link Control Protocol (LCP), Logical Link Control and Adaptation Protocol (L2CAP), Service Discovery Protocol (SDP) and Serial Port Emulation Protocol (RFCOMM ). Among them, the baseband and link controller and the link management protocol belong to the low-level transmission protocol. Their functions focus on the physical realization of voice and data wireless transmission and the connection and networking between Bluetooth devices. These functions are integrated in the Bluetooth hardware module. , application developers for high-level protocols do not need to care about the details of these low-level protocols; Logical Link Control and Adaptation Protocol and Host Control Interface (HCI) belong to high-level transmission protocols, which shield high-level application profiles such as frequency hopping sequences Select and other low-level transmission operations, and provide high-level applications with more beneficial and more effective data packet formats; based on the TS07.10 standard of the European Telecommunications Standards Institute (ETSI), the serial port emulation protocol (RFCOMM) has been formulated; this protocol uses In order to simulate the working environment of the serial port, the traditional application based on the serial port can directly run on the protocol layer without any modification or only a small amount of modification; the Service Discovery Protocol (SDP) is used to realize the mutual query between Bluetooth devices and Ability to access services provided by the other party.2. Bluetooth upper layer application frameworkThe Bluetooth application protocol profile refers to the application software located on the upper layer of the Bluetooth protocol stack and the protocols involved, including the development of Bluetooth applications that drive functions such as voice communication and dial-up Internet access. All kinds of Bluetooth products have developed corresponding application frameworks for them by SIG. The application framework mainly defines some common functions or the protocols used to realize specific Bluetooth products, the interoperability requirements of each Bluetooth protocol, and the realization functions of each function.Bluetooth application frameworks can be divided into five categories:(1) Application framework: The application framework in the general application model is the basis of all other application frameworks. They specify the application frameworks in other application models and are the functional processes commonly used by all other application frameworks, such as device query, connection Establish and discover services, etc.; (2) Bluetooth phone application framework: application framework related to voice applications and phone control; (3) Bluetooth networking application framework: use Bluetooth devices to provide users with the establishment of personal local area networks and wireless access Public switched telephone network; (4) Object exchange application class framework: used to realize interoperability applications of different types of data objects, such as files, electronic business cards, images, etc.; (5) Bluetooth audio and video application framework: based on network applications audio and video transmission, control, and distribution applications.3. Bluetooth networking technologyBluetooth technology is a short-distance wireless communication technology that supports point-to-point or point-to-multipoint data and voice services. The Bluetooth system adopts a flexible networking method without a base station, so that a Bluetooth device can be connected to other multiple Bluetooth devices at the same time, thus forming a Bluetooth piconet (Piconet); a Bluetooth piconet can be just two connected devices (such as As shown in Figure 2.12a), such as a laptop and a mobile phone, or multiple devices connected together (as shown in Figure 2.12b); the Bluetooth piconet adopts a master-slave When the network was first built, one of the Bluetooth devices was defined as the master device, and the rest were slave devices; a master device can communicate with up to seven slave devices at the same time, and the slave devices here are called active slave devices (ActiveSlave); but at the same time There can be multiple dormant (Parked) slave devices belonging to the master device; these dormant slave devices do not perform actual effective data transmission and reception, but still maintain clock synchronization with the master device so that they can quickly join the piconet in the future. Regardless of the state of the device, whether it is a dormant slave device or an active slave device, the master device of the piconet controls the parameters of the channel. In the piconet, the master device communicates with all active slave devices through a certain polling method, and uses methods such as designated time slots to enhance the communication between the master and the slave and the communication between the slave and the slave.Bluetooth Scatternet (Scatternet) is formed by interconnecting multiple piconets. As shown in Figure 2.12c/2.13, a scatternet is a bluetooth network with a larger coverage area than a piconet composed of overlapping piconets. The slave device can join different piconets through the time division multiplexing mechanism, and the master device of one piconet can become the slave device of another piconet. Each piconet has its own frequency hopping sequence, and there is no frequency hopping synchronization between them, which reduces the interference of the same frequency.The above are the details of the Bluetooth protocol stack architecture and networking technology introduced by Shenzhen Zuchuang Microelectronics Co., Ltd. If you have Bluetooth product design and development needs, you can trust us. We have rich experience in custom development of smart electronic products. We can evaluate the development cycle and IC price as soon as possible, and can also calculate the PCBA quotation. We are a number of chip agents at home and abroad: Songhan, Yingguang, Jieli, Ankai, Quanzhi, realtek, with MCU, voice IC, BLE Bluetooth IC, dual-mode Bluetooth module, wifi module. We have hardware design and software development capabilities. Covering circuit design, PCB design, single-chip microcomputer development, software custom development, APP custom development, WeChat official account development, voice recognition technology, Bluetooth development, wifi technology, etc. It can also undertake the research and development of smart electronic products, the design of household appliances, the development of beauty equipment, the development of Internet of Things applications, the design of smart home solutions, the development of TWS earphones, the development of Bluetooth earphone speakers, the development of children's toys, and the research and development of electronic education products.
06-23

2023

Bluetooth anti-electromagnetic interference performance

Test and Analysis of Anti-electromagnetic Interference Performance of Bluetooth TechnologyThe common frequency band of Bluetooth technology in the world is 2.4GHz. Due to the strong openness of its frequency band range, it is inevitable to be subject to external electromagnetic interference during use, which affects the stability and security of data transmission. It is conducive to the wide application of bluetooth technology. Therefore, it is of great significance to explore the anti-electromagnetic interference performance of bluetooth technology and propose improvement countermeasures.1. Overview of Bluetooth technologyBluetooth is a radio technology suitable for short-range communication between devices, enabling real-time transmission and sharing of data. For example, the application of Bluetooth technology in mobile phones, PDAs, wireless headsets, notebook computers and emerging wearable devices can realize real-time transmission and sharing of information. Through the full use of Bluetooth technology, the speed of data transmission can be effectively improved, the communication process between mobile devices can be simplified, and a good foundation has been laid for the research of wireless communication. Bluetooth adopts distributed network structure and frequency hopping spread spectrum technology, supports point-to-point and point-to-multipoint communication, and its data rate can reach 24Mbit/s. At the same time, Bluetooth technology adopts a time-division duplex transmission scheme, which can fully realize full-duplex transmission, and has higher advantages compared with traditional data transmission methods.1.1 Bluetooth technical characteristicsBluetooth technology is a wireless communication technology integrating low power consumption, short-distance data transmission and openness. It is jointly released by Intel Ericsson, Nokia, Toshiba and International Business Machines Corporation. On the basis of making full use of short-distance and low-cost wireless transmission technology, Bluetooth technology establishes a complete short-range wireless connection station between fixed equipment and wireless communication equipment, which can realize real-time data transmission within a specific range. In fact, Bluetooth technology is to realize the effective control of software by establishing radio and radio air interface, that is to say, Bluetooth technology is an organic combination of computer technology and communication technology. The technical characteristics of Bluetooth mainly include the following points: 1) low power consumption; 2) low cost; 3) short distance; 4) high security: 5) real-time performance; 6) high-speed frequency hopping. Bluetooth technology can link various mobile devices, fixed communication devices, computers and other wearable devices in a network at the lowest cost within a short distance to form a peripheral interface for data transmission.1.2 Main features of Bluetooth technologyFirst, Bluetooth technology uses the open ISM frequency band in the industrial, medical and scientific fields. The working range is 2.4GHz~2.4835GHz. for convenience. Second, Bluetooth technology can realize short-distance data transmission, and its working distance generally does not exceed 10m, and the maximum can be increased to 100m. By expanding the working range of Bluetooth, on the basis of ensuring the data transmission rate, effective immunity to electromagnetic interference can be realized, which has high security. Third, by increasing the application of frequency hopping and spread spectrum technology, Bluetooth technology usually divides 79 frequency points in the 2.4GHz~2.4835GHz frequency band, adopts a fast hopping rate, and the speed of data transmission is significantly improved compared with before. Anti-interference performance is also higher. Fourth, Bluetooth technology adopts time-division multiplexing multiple access technology: the data is packaged into data packets and transmitted in units of time slots. In this way, the problems of "collision" and "hidden terminals" in wireless communication are solved.2. Anti-electromagnetic interference type of Bluetooth technologyThe types of electromagnetic interference in Bluetooth technology mainly include two types: suppressing electromagnetic interference and avoiding electromagnetic interference. Avoiding electromagnetic interference refers to effectively avoiding electromagnetic interference by reducing the transmission signal level between each unit, while suppressing electromagnetic interference requires spread spectrum technology and recoding. For example, when the power is greater than 50dB and the environment is different, in order to ensure the rate of Bluetooth technology up to 24Mb/s, it is difficult to achieve only relying on coding technology, because electromagnetic signals are easier to interfere in a lower power environment, so the power should be selected sent in higher cases. If the time avoidance method is adopted, once strong electromagnetic interference occurs, the data transmission will be interrupted. At the same time, because some wireless communication devices are greatly affected by the bandwidth, between 2.4GHz and 2.4835GHz, the frequency of wireless communication devices With a bandwidth of 80MHZ, it is possible to find a frequency spectrum without electromagnetic interference, and use a filter to filter it to achieve effective suppression of electromagnetic interference. Accordingly, it is considered that the application of the frequency domain interference avoidance method in the Bluetooth technology data transmission process is strengthened, and the security of data transmission is higher.3. Anti-electromagnetic interference performance test and analysis of Bluetooth technologyRealizing short-distance wireless transmission of data is the fundamental goal of Bluetooth technology application. At this stage, Bluetooth technology has been widely used in short-range communication with its advantages of high transmission speed and simplicity and convenience, and has a good application prospect in the field of home and office. But at this stage, the data transmission stability of Bluetooth technology needs to be further improved, and the anti-noise and electromagnetic interference performance needs to be improved. In this study, microwave ovens commonly used in households are selected as the research object, and its working range is 2.4GHZ. The factors affecting the anti-interference performance of Bluetooth communication technology are explored, and the report is as follows.3.1 Bluetooth anti-jamming experimental instruments and equipmentIn this study, the microwave oven is used as the main interference source, and the operating frequency of the microwave oven is 2450MHZ. The stopwatch is used as a time measurement tool, and the size of the transfer file is mainly 100K and 18O0K.3.2 Experimental Principle of Bluetooth Anti-jammingIn this study, two test files with different sizes are selected, namely 1800K and 1OOK. During the experiment, the distance between the Bluetooth transceiver is set as dl, and the distance between the interference source and the Bluetooth transceiver is d2. Research the data transmission rate under the condition of different distances between the interference source and the Bluetooth open system. In the process of testing the influence of interference sources on voice transmission, the voice distortion is mainly tested by the senses.3.3 Bluetooth anti-jamming experimental resultsThrough in-depth analysis of the results of this study, we can see that the design of the Bluetooth communication system is more scientific and reasonable. In the process of transmitting small files, the influence of interference sources on file transmission is almost non-existent. In the process of transmitting large documents, the Bluetooth system only has a slight impact on the transmission speed and time when the distance from the interference source is the closest. Tests of speech transmission under normal conditions under various conditions showed no speech distortion.At the same time, after this test analysis, it can also be known that the interference source selected in this research-the microwave oven has a small transmission power, which is also the main reason why the noise interference has no obvious impact on the transmission time and rate of the Bluetooth system. It proves that the application of the Bluetooth system in the family has high feasibility, and its anti-jamming performance is enough to meet the family's demand for Bluetooth anti-jamming performance. However, in the process of applying the Bluetooth system in the industrial, medical and scientific fields, the transmission power of the interference source is much higher than that of the induction cooker, which poses a huge challenge to the anti-interference ability of the Bluetooth system. Therefore, in order to achieve high-quality communication, it is necessary to further improve the anti-electromagnetic interference performance of the Bluetooth system.4. Effective countermeasures to improve the anti-electromagnetic interference performance of Bluetooth technology4.1 Analysis of the interference problem in the Bluetooth working frequency bandThe electromagnetic interference problem of the Bluetooth system operating in the 2.4GHZT frequency band mainly has the following two points: First, it comes from the electromagnetic interference inside the Bluetooth system. In the process of designing the internal circuit and interface of Bluetooth, if there is an unreasonable design phenomenon, it will cause the high-frequency electromagnetic radiation inside the Bluetooth system to radiate outwards, which will reduce the stability of the internal circuit of the Bluetooth system and is not conducive to improving the transmission of the Bluetooth system. speed. Second, electromagnetic interference from existing services. At this stage, although the communication between high-frequency Bluetooth devices generally relies on frequency hopping and direct sequence spread spectrum, and its transmission power is also within the range allowed by the country, it is affected by the antenna form, system structure and gain index of the Bluetooth system. Modulation schemes, frequencies, and guard bands of communication equipment all have significant differences. In addition, the 2.4GI-IZ frequency band has strong openness, and the use of the frequency band is more complicated, which increases the source of electromagnetic interference.4.2 Bluetooth anti-jamming solutionFirst, for the internal interference of the Bluetooth system, designers should pay attention to improving the rationality of the circuit design of the Bluetooth system in the process of improving the Bluetooth system, so as to minimize the electromagnetic interference. Second, in view of the electromagnetic interference from the existing business, the designers need to focus on the research on the electromagnetic interference between the unified frequency Bluetooth system on the basis of arranging the radio frequency command for the wireless business, and rely on the frequency hopping technology to realize the anti-electromagnetic interference effective resistance. For example, a designer has strengthened the application of adaptive frequency hopping technology in the Bluetooth system in response to the problem of electromagnetic interference, enabling the Bluetooth system to automatically adjust its own frequency range in different situations to achieve effective avoidance of current electromagnetic interference , improve the pertinence of frequency hopping, and achieve effective resistance to electromagnetic interference. Through the application of adaptive frequency hopping technology, the environmental applicability of the Bluetooth system can be fully improved, and on the basis of ensuring data transmission time and rate, it can effectively resist electromagnetic interference and has high application value. In summary, through the test and analysis of the anti-electromagnetic interference performance of Bluetooth technology, it is found that the transmission power of the interference source, the internal interference of the Bluetooth system, and the existing services will have a certain impact on the anti-interference ability of the Bluetooth system.SummarizeThrough research, it is found that the transmission power of the interference source is an important factor affecting the transmission speed of Bluetooth technology. Therefore, in order to fully improve the anti-interference performance of Bluetooth technology, the internal and external circuit design of the Bluetooth system should be continuously improved, the application of adaptive frequency hopping technology should be increased, and the anti-electromagnetic interference ability of the Bluetooth system should be comprehensively improved.The above are the details of the test and analysis of Bluetooth anti-electromagnetic interference performance introduced by Shenzhen Zuchuang Microelectronics Co., Ltd. If you have Bluetooth product design and development needs, you can trust us. We have rich experience in custom development of smart electronic products. We can evaluate the development cycle and IC price as soon as possible, and can also calculate the PCBA quotation. We are a number of chip agents at home and abroad: Songhan, Yingguang, Jieli, Ankai, Quanzhi, realtek, with MCU, voice IC, BLE Bluetooth IC, dual-mode Bluetooth module, wifi module. We have hardware design and software development capabilities. Covering circuit design, PCB design, single-chip microcomputer development, software custom development, APP custom development, WeChat official account development, voice recognition technology, Bluetooth development, wifi technology, etc. It can also undertake the research and development of smart electronic products, the design of household appliances, the development of beauty equipment, the development of Internet of Things applications, the design of smart home solutions, the development of TWS earphones, the development of Bluetooth earphone speakers, the development of children's toys, and the research and development of electronic education products.
06-22

2023

The principle of car bluetooth technology

The principle of bluetooth technology and its application in the field of automobileBluetooth is a wireless communication technology that supports short-distance communication of devices (usually within 10 meters). Data communication between many devices such as peripherals. Bluetooth can effectively simplify the communication between mobile communication terminal equipment and between equipment and the Internet, so that data transmission becomes more rapid and efficient.With the development of science and technology, Bluetooth technology is playing an increasingly important role. Bluetooth technology is closely related to people's lives, and people's demand and dependence on Bluetooth are increasing day by day. This paper analyzes the principle of bluetooth technology, and discusses the application of bluetooth technology in the field of automobiles.1.The principle of Bluetooth technology1.1 Bluetooth protocol stackFigure 1 shows a schematic diagram of the bluetooth protocol stack architecture. The goal of the Bluetooth protocol is to allow applications that follow the specification to interoperate. To achieve interoperability, applications on communicating devices must run on the same protocol stack. So far, the Bluetooth protocol has 1.0, 1.1, 1.2, 2.0, 2.1, 3.1, 4.0, 4.1 and other versions. With the evolution of the protocol and the development of technology, the data rate is gradually increased. The 1.0 version of Bluetooth is the basic bit rate (BR, Basic Rate), the maximum physical layer data rate is 1Mbps; the 2.0 version is the enhanced bit rate (EDR, Enhanced Data Rate), and its physical layer data transmission rate is increased to 2Mbps or 3Mbps; the 3.0 version The introduction of alternative radio frequency technology (AMP, Alternative MAC PHY), using IEEE 802.11 to achieve a physical layer data rate up to several 100Mbps. Version 4.0 introduced Bluetooth Low Energy (BLE, Bluetooth LowEnergy). From the perspective of protocol support, Bluetooth devices can be basically divided into three categories: classic devices, dual-mode devices (supporting both classic Bluetooth and BLE), and single-mode devices (only supporting BLE). Single-mode devices are called Bluetooth Smart, and dual-mode devices are called Bluetooth SmartReady. It should be noted that single-mode devices can only communicate with dual-mode devices, not classic Bluetooth.Figure 1 Schematic diagram of the bluetooth protocol stack architecture(1) The radio frequency (RF, Radio Frequency) layer defines the frequency band and channel arrangement, the requirements that transmitters and receivers working in this frequency band should meet, etc., and realizes the filtering and transmission of data streams.The baseband (BB, Baseband) layer protocol provides two physical links: a connection-oriented synchronous mode (SCO, Sychronous Connection-Oriented) and a connectionless asynchronous mode (ACL, Asychronous Connection-Less).Link Management Protocol (LMP, Link Manager Protocol) is responsible for link establishment, control and link security. LMP performs identity authentication and encryption through connection initiation, exchange, and verification, and determines the size of baseband data packets through negotiation; LMP controls the energy-saving mode and work cycle of wireless devices.The host control interface (HCI, Host Controller Interface) is the interface between the underlying hardware and the upper layer protocol, providing instructions for accessing hardware functions such as baseband, link controller, link manager, and status registers.(2) Logical Link Control and Adaptation Protocol (L2CAP, LogicalLink Control and Adaptation Protocol) belongs to the data link layer. L2CAP provides connection-oriented and connectionless data services for upper-layer protocols. Segmentation and reorganization and delivery of quality of service. L2CAP allows high-level protocols to send and receive data packets in 64K bytes, and L2CAP only supports ACL. The priority of sending LMP messages is higher than that of user information, so the messages sent by LMP will not be delayed due to L2CAP communication. LMP is mainly used to control data transmission, while L2CAP provides packet transmission and control to the upper layer.(3) The Bluetooth Telephone Control Protocol (TCS-BIN) defines call control signaling for establishing voice and data calls between Bluetooth devices, and handles the mobility management process of TCS devices. AT-commands defines a set of commands for controlling mobile phones and modems in multi-user mode.(4) AVCTP (Audio/Video Control Transport Protocol) describes the exchange message transmission mechanism of A/V equipment. AVDTP (Audio/Video Distribution Transport Protocol) defines the negotiation, establishment and transmission mechanism of A/V streams.(5) Service Discovery Protocol (SDP, Service Discovery Protocol) is a protocol based on the client/server structure, and the client application discovers the existing server and its attributes through SDP. SDP only provides mechanisms for discovering services, but not methods for consuming those services. Almost all Bluetooth devices support the SDP protocol, except for the Bluetooth devices that only do Client.(6) Cable emulation protocol The RFCOMM protocol is a serial port emulation protocol based on the technical standard (ETSI) 07.10 of the European Telecommunications Standards Institute. The RFCOMM protocol provides emulation of the RS-232 serial port on L2CAP.(7) Attribute protocol (ATT, Attribute protocol) was introduced for BLE in version 4.0, which allows devices to show device capabilities to other devices in the form of "attributes".(8) Bluetooth Network Encapsulation Protocol (BNEP, Bluetooth Network Encapsulation Protocol) directly bears IPv4/IPv6 through L2CAP.(9) OBEX defines data objects and communication protocols for exchanging these objects, and OBEX is also used for IrDA simulation. In Bluetooth protocol version 1.0, OBEX is carried by RECOMM, while in BR/EDR, OBEX is based on TCP/IP carried by BNEP.1.2 Bluetooth application scenarios and profilesAs shown in Figure 1, according to the purpose of the protocol and its association with the Bluetooth Special Interest Group (SIG), Bluetooth protocols can be classified into the following categories:(1) Bluetooth Core Protocols (Bluetooth Core Protocols), including RF, BB, LMP, L2CAP, SDP, and AUDIO; (2) Adaptation protocols, including RFCOMM, ATT, and BNEP; (3) Telephony Control Protocols , including TCS Binary and AT-commands; (4) A/V control protocols, including AVCTP and AVDTP; (5) Reference protocols (Adopted Protocols), including PPP, UDP/TCP/IP, OBEX, WAP/WAE, vCard/ vCal and IrDA. For specific Bluetooth application scenarios (Bluetooth Usage Models), in order to maintain compatibility and interoperability between Bluetooth devices more easily, the Bluetooth specification introduces Profile.Profile defines the protocol covered by an application scenario and the features necessary to support Bluetooth device communication. The most basic profiles are general access applications (GAP, Generic Access Profile) and general attribute applications (GATT, Generic Attribute Profile). GAP carries traditional BR /EDR, while GATT carries BLE. Figure 2 illustrates the hierarchical relationship between the Bluetooth protocol and Profile.Figure 2 Bluetooth Profile and protocol hierarchy relationshipIn addition to GAP, commonly used profiles include SDAP (Service Discovery Application Profile), SPP (Serial Port Profile), and GOEP (Generic Object Exchange Profile). The Profile list adopted by the Bluetooth SIG can be found on the Bluetooth development portal (http://developer.bluetooth.org). The Hands-Free Application Protocol Framework HFP mentioned below is one of them.1.3 Typical Bluetooth system frameworkA typical Bluetooth system includes a wireless unit, link controller, link management and interface, software protocol, and host terminal.As shown in Figure 3, the host terminal is responsible for functional modules and Bluetooth communication control, and other modules implement Bluetooth communication.In practical applications, the chip basic circuit set that integrates several Bluetooth functions is usually called a Bluetooth module, and subsequent development is carried out on the basis of the Bluetooth module, which greatly simplifies the development of Bluetooth applications.The world's major chip manufacturers are actively investing in the research and development and testing of Bluetooth modules, and have launched Bluetooth modules covering different protocol stack levels. For example, CSR in the UK owns or once owned three kinds of Bluetooth modules, HCI ROM, HCI RFCOMM ROM and Full embedded solution.(1) HCI ROM only covers the protocol layer below HCI. The hardware HCI interface usually uses UART/USB/SDIO, while the L2CAP protocol layer in Figure 1 needs software implementation and runs on an external processor.(2) The difference between HCI RFCOMM ROM and HCI ROM is that it integrates RFCOMM and L2CAP into the chip, which can reduce the code amount of the host processor, but the data throughput rate will be affected.(3) Full embedded solution covers all protocol layers of Bluetooth, and the most popular one is this Bluetooth module.2.The application of Bluetooth technology in the automotive fieldWith the maturity and development of bluetooth technology, bluetooth technology has been used more and more widely, and the automotive field is one of the most active fields. According to the statistics of ABI Research, it is estimated that by 2017, there will be 60 million cars equipped with Bluetooth technology. Compared with 2013, the market growth rate has increased by 47%.2.1 Car hands-free systemCar hands-free system is a typical application of Bluetooth technology in the automotive field. The system uses the mobile phone as the gateway, and the mobile phone supporting the Bluetooth function can be placed anywhere within 10 meters of the vehicle-mounted hands-free system. call.The Hand Free Profile (HFP) specifies the minimum set of functions required for a mobile phone to interact with a hands-free device (vehicle or headset) via Bluetooth. The protocol stack of the Hand Free Profile is shown in Figure 4. HFP defines two roles: voice gateway (AG, AudioGateway) and hands-free unit (HF, Hand-free). Among them, the voice gateway provides audio input and output and its control, and the typical voice gateway is a Bluetooth mobile phone; the hands-free unit provides remote control function, and can use the vehicle-mounted hands-free equipment.2.2 Vehicle detection system based on Bluetooth OBDThe on-board diagnostic system (OBD, On-Board Diagnostics) can monitor the working conditions of the engine electronic control system and other functional modules of the vehicle in real time during the running of the vehicle. Stored on memory within the system as diagnostic trouble codes. With the improvement of various sensors and electronization of vehicles, OBD has added various monitoring functions.As the communication interface of the on-board monitoring system, the OBD interface can provide data such as fuel consumption records, battery voltage, air-fuel ratio, throttle opening, and the number of knocks, in addition to reading fault codes for vehicle repair. The data can be read out through a dedicated data cable and then displayed on the matching display screen. The more convenient way is to add a Bluetooth OBD interface adapter and a smart phone software. At present, many kinds of Bluetooth OBD modules are launched on the market, and the data read by the OBD interface are transmitted to the smart phone through Bluetooth, and then presented to the user through the software of the mobile phone.2.3 Bluetooth Rearview MirrorBluetooth rearview mirror is to add Bluetooth technology to the rearview mirror of the car, so that the rearview mirror can increase the hands-free call function. quality.SummarizeIn addition to the automotive field, the typical application fields of Bluetooth technology include wireless office, information appliances, medical equipment, school education and factory automatic control. It can be predicted that with the advancement of technology and the reduction of production costs, the application field of Bluetooth technology will expand, which will further change people's life and work methods, and significantly improve the quality of life and work.The above is the principle of Bluetooth technology and its application in the automotive field introduced by Shenzhen Zuchuang Microelectronics Co., Ltd. If you have Bluetooth product design and development needs, you can trust us. We have rich experience in custom development of smart electronic products. We can evaluate the development cycle and IC price as soon as possible, and can also calculate the PCBA quotation. We are a number of chip agents at home and abroad, including MCU, voice IC, BLE Bluetooth IC, dual-mode Bluetooth module, and wifi module. We have hardware design and software development capabilities. Covering circuit design, PCB design, single-chip microcomputer development, software custom development, APP custom development, WeChat official account development, voice recognition technology, Bluetooth development, wifi technology, etc. It can also undertake the research and development of smart electronic products, the design of household appliances, the development of beauty equipment, the development of Internet of Things applications, the design of smart home solutions, the development of TWS earphones, the development of Bluetooth earphone speakers, the development of children's toys, and the research and development of electronic education products.
07-19

2023

Inkjet Manufacturing Technology for Circuit Boards

Inkjet printing is also called inkjet printing. As a printing process, it can be used for graphic transfer like lithography and screen printing. Inkjet printing is a non-contact physical printing process. It does not need to use chemical potions, and it does not use printing plates or films to print like movable type printing and exposure photography. It only needs to output the printed graphics directly from the computer and control them through the controller. The nozzle of the inkjet system ejects ink particles from the nozzle to form a pattern. The manufacturing process of the traditional PCB circuit is very complicated. It needs to go through the image transfer process, make the metal adhere to the substrate, form the etching manufacturing process of the circuit, and finally appear the desired circuit on the substrate. The current image transfer technology has reached the limit of the line width, and can no longer increase the packaging density. In contrast, using inkjet technology, there is no need to change the production line and prepare components, and only need to directly input the CAD data into the inkjet printing device to achieve the purpose of changing the line. However, the current inkjet technology for printed circuit boards is only limited to a certain step in the numerous manufacturing processes of printed circuit boards, and cannot fundamentally solve the many serious chemical problems of printed circuit board products due to the lengthy process. Pollution, waste gas pollution, high energy consumption and other environmental issues.1. Technical scheme of full inkjet manufacturing of circuit boardsThe full inkjet manufacturing method of the circuit board is to first print the conductive layer, insulating layer, interlayer via hole, solder mask and protective layer on the carrier board according to the computer output graphics, and then print the character layer, components, etc., through layer by layer printing technology, and finally realize the full inkjet manufacturing of the entire circuit board. This technical method can greatly shorten the manufacturing and processing process of printed circuit boards, shorten the original dozens of technological processes to only a few technological processes, and reduce the cost of resources such as production plants, personnel and supporting facilities. Invest in waste. The product processing of this technology does not involve any chemical potion and gas, no waste liquid and waste gas are produced, and meets the national environmental protection requirements. Carbon saving concept. This technical method is also applicable to the processing of metal-based circuit boards, thick copper printed circuit boards, embedded capacitance embedded resistance circuit boards, semiconductor IC substrates and other products, including integrated circuits of various organic and inorganic electronic components, such as electrodes, transistors, etc. , inductors, capacitors, resistors, batteries and other functional components.2.The technical steps of the full inkjet manufacturing method of the circuit board(1) According to the layout design requirements of the circuit board, prepare a carrier board with the same size and place it in the inkjet printer;(2) Input the inner circuit pattern into the inkjet printer through the computer, print the circuit pattern with conductive ink, and print out the non-circuit pattern area with insulating resin ink to manufacture a single-layer inner circuit board;(3) After the inner circuit board is heat-pressed and leveled, heat-cured or light-cured, repeat steps 1 and 2 to form a multi-layer inner circuit with a conductive layer, a via hole and an insulating layer whose thickness meets the design requirements plate;(4) Separate the multi-layer inner layer circuit board and the carrier board, and the special function carrier board may not be separated;(5) Use conductive ink to inkjet print the outer conductive layer pattern of the circuit board on the upper and lower surfaces of the multilayer inner layer circuit board, and perform hot pressing leveling and heat curing or light curing treatment;(6) Use solder resist ink and protective ink to inkjet print the solder resist pattern and protective pattern on the surface of the outer circuit board, and perform hot pressing leveling and heat curing or light curing treatment;(7) Use character ink to inkjet print character marking patterns on the surface of the finished circuit board, and perform heat curing or light curing treatment;(8) Carry out appearance processing on the printed circuit board to form the final multi-layer printed circuit board;(9) Various other inorganic and organic electronic functional structural materials can also be integrated into circuit boards by this method.The carrier board in the scheme can be made of paper, metal, glass, ceramic or resin materials, and flexible or rigid materials can be selected according to functional requirements. The inkjet printer can be a common household printer, such as an improved Epson printer. Different types of inks are output according to the colors designed by the computer, and are placed in the corresponding printer cartridges to ensure good printing efficiency. Among them, the conductive ink can use nano-silver or nano-copper and its oxide conductive ink; the insulating ink can use epoxy resin, polyphenylene ether, polyimide, etc. and its modified resin ink; solder resist ink and character ink are both Ordinary epoxy resin-based solder resist and character inks; protective inks are solder paste-based soldering inks. For the hot pressing leveling, a temperature-controlled electric iron can be used for hot pressing leveling of the semi-finished circuit board to ensure a flat and good printing interface. The appearance processing adopts methods such as laser cutting or mechanical cutting. The thickness of the conductive layer is 2-20 μm, the height of the via hole is 5-50 μm, the thickness of the insulating layer is 5-75 μm; the heat curing temperature is 80-200 ° C, and the time is 2-60 min; the light curing type is UV light curing , the curing time is ~30 min; the hot-press leveling temperature is 50~100°C, and the pressure is 1~50 kg.3. Implementation effect of full inkjet manufacturing of circuit boardsProvide a technical method for full inkjet manufacturing of circuit boards (as shown in Figure 1). This method can not only accurately control graphics, is easy to operate, greatly shortens the circuit board processing process, and does not involve any chemical liquid or gas process, so It is a low-carbon, energy-saving, and environmentally friendly printed circuit board manufacturing process that produces waste liquid and exhaust gas, while greatly reducing the waste of raw materials. It can make printed electronic circuits develop into a brand-new electronic processing process, a brand-new craft technology.With the continuous research and development of inkjet printing technology, inkjet printing technology has made great breakthroughs and progress. Especially in recent years, major breakthroughs and progresses have been made in inkjet printing machines, inkjet print heads, and inks, such as the super inkjet printing technology developed by the Japan Industrial Technology Research Institute, which can eject ink droplets as small as 1~2 pL device of. There are also UV curable jet printing inks suitable for large-scale production, especially the developed silver-containing nanoscale inks, which provide conditions for the production of PCB products with a line width/spacing as fine as 10-20 μm. In recent years, a more advanced super inkjet printing technology has been developed, the size of the jetted ink droplet can be as small as 1 μm or less, so that a line with a line width of less than 3 μm can be formed.SummarizeThe full inkjet manufacturing technology of circuit boards can easily achieve the purpose of energy saving and emission reduction without using expensive production equipment and environmental protection facilities. This method does not require a mask, and there is almost no "three wastes" in the production process, which improves environmental pollution and realizes green production. This technology can be applied to substrates such as rigid boards and flexible substrates, and can realize highly automated production methods, and multiple nozzles can operate in parallel, thereby increasing production capacity. It can be used in three-dimensional packaging and 3D circuit board manufacturing, and can realize the integration of active and passive functional parts. At the same time, due to the low melting point of metal nanomaterials, the curing temperature of metal lines is as low as 200~300°C. Because of these advantages, inkjet printing technology will be rapidly promoted and applied in the PCB industry, becoming the mainstream of PCB product production, and bringing revolutionary changes and progress to the PCB industry.The above is the full inkjet manufacturing method of the circuit board introduced by Shenzhen Zuchuang Microelectronics Co., Ltd. for you. If you have software and hardware function development needs for smart electronic products, you can rest assured to entrust them to us. We have rich experience in customized development of electronic products, and can evaluate the development cycle and IC price as soon as possible, and can also calculate PCBA quotations. We are a number of chip agents at home and abroad, including MCU, voice IC, Bluetooth IC and modules, wifi modules. We have hardware design and software development capabilities. Covering circuit design, PCB design, single-chip microcomputer development, software custom development, APP custom development, WeChat official account development, voice recognition technology, Bluetooth wifi development, etc. It can also undertake the research and development of smart electronic products, the design of household appliances, the development of beauty equipment, the development of Internet of Things applications, the design of smart home solutions, the development of TWS solutions, the development of Bluetooth audio, the development of children's toys, and the development of electronic education products.

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