Remote control car bluetooth control board solution development

1. Technology used in the design of smart toy electric cars

1.1 SCM Technology

A single-chip microcomputer (Single Clip Microcomputer) is mainly composed of a central processing unit, a read-only memory, a random access memory, a timer/counter, and an input-output interface circuit. These units with different functions are integrated on the same chip. A complete microcomputer system can be formed.

The single-chip microcomputer develops rapidly, and various high-performance single-chip microcomputers continue to develop. So far, microcontrollers suitable for different fields have appeared one after another. It is characterized by fast computing speed, large storage capacity and strong computing ability. There are general-purpose and special-purpose types. The characteristics of the single-chip microcomputer determine its wide range of applications. The single-chip microcomputer has become an intelligent tool in various fields such as agriculture, industry, national defense, education, scientific research and daily life.

1.2 Smart Toy Electric Vehicle Technology

With the rapid development of computer science, sensor technology, artificial intelligence technology and other related disciplines, electric toy cars are developing in the direction of intelligent control. The intelligent electric vehicle control system includes computer control technology, sensor technology, mechanical engineering and artificial intelligence, etc. It can be said that it is a comprehensive control system, which not only includes single-chip control methods, but also optical sensor control mode, and some even have voice control mode and so on. Its overall function is to perceive the external environment, perform dynamic analysis and decision-making, and further develop behavior control and execution.

2. The overall design of the smart toy car

2.1 The overall block diagram of the smart toy car system

According to the requirements of the design idea, using single-chip microcomputer control, the overall block diagram of the system is designed as shown in Figure 1, which mainly includes modules such as main control, detection, obstacle avoidance, motor drive and display.

2.2 Design and analysis of each module of the toy car

(1) Main control module: Nowadays, electronic products with intelligent functions generally use single-chip microcomputer as the main controller, but now there are many types of single-chip microcomputer products with different functions. Commonly used are Intel's MCS-51 series single-chip microcomputer, Ateml company's AT89 series single-chip microcomputer and so on. Since this system is a relatively complex control system, it needs to have multi-switch input, so the STC89C51 single-chip microcomputer of Ateml Company is selected. This single-chip microcomputer is suitable for processing multi-switch values.

(2) Detection module: There are many solutions that can be adopted by the detection module, such as the use of ultrasonic detectors, which have the characteristics of long measurement distances, but ultrasonic ranging also has certain blind spots, so it may lead to inaccurate measurement problems; Another example is the use of video capture devices. This method can achieve the highest accuracy, but the relative cost will be greatly increased, so it is generally not used in toy electric vehicles.

In view of comprehensive considerations, this paper chooses photoelectric tube detection, but the problem that needs to be paid attention to in this scheme is the detection distance of photoelectric tubes. The braking distance of toy car motors is at least 10cm, so it is necessary to choose photoelectric tubes to ensure complete obstacle avoidance. The detection distance is greater than 10cm, so as to ensure the accuracy of detection.

(3) Obstacle avoidance module: For the comparison of the schemes of the detection module, the obstacle avoidance module uses infrared paired tubes for obstacle avoidance detection, and installs six infrared paired tubes in the front, left front, right front, back, and left of the toy car. The rear and right rear adopt the reflective receiving method, that is, only when the object reflects infrared light back can there be signal input, and the signal strength is proportional to the distance.

Among them, four sensors can be used to detect some obstacles that are relatively close to the car, and the detected signals are sent to the P2.0-P2.3 port of the microcontroller, and the other two sensors can be used to detect some obstacles that are far away objects, and send the detected signal to the P2.5 port and P2.6 port of the microcontroller.

(4) Motor drive module: This system uses sensors to form a signal detection circuit to detect information such as the running speed and position of the electric vehicle in real time, and receives signals through a single-chip microcomputer and issues instructions for intelligent control. The motor drive module can use L298N, which integrates an H-bridge drive circuit inside, so it can be used to drive the motor. The system uses the microcontroller to send a PWM signal to the L298N circuit to control the speed of the car and start and stop functions.

(5) Display module: The liquid crystal display has the characteristics of low power consumption, no radiation, stable image, and good picture effect. In addition, the connection circuit between the liquid crystal display and the single-chip microcomputer is relatively simple, and it occupies less I/O ports. Therefore, this article uses a liquid crystal display (LCD1602) to display information such as time and distance, and can display some Chinese characters, making the interface more intuitive.

(6) Power supply module: A dry battery pack is used for power supply, which can not only reduce the load of the toy electric car, but also obtain a more stable voltage. In this paper, four dry batteries can be used to obtain 5V through step-down as the power supply system for the microcontroller and other unit circuits, and six dry batteries can be used as the power supply system for the motor and photoelectric switch. In this way, the voltage interference to the single-chip microcomputer and other unit circuits can be well avoided when the motor is started, and the normal operation of the system can be guaranteed.

3. Performance analysis of toy car system

System noise may cause problems such as program counter state errors, which will lead to errors in the overall program operation, so how to improve reliability must be considered in this system. The anti-interference scheme proposed in this article has certain effects, but if you want the program to run reliably and encounter problems such as emergencies and automatic recovery, you need to consider improving it from software design. To improve reliability, various measures can be taken in the software program, such as digital filtering, setting traps, instruction redundancy, etc.

epilogue

The system introduced in this paper uses the signal detection circuit composed of sensors to monitor the running speed, running position and running status of the toy electric car in real time, receives the signal through the single chip microcomputer, and processes various data information obtained by the detection circuit, and then Then the single-chip microcomputer sends out the correct control command, so that the electric vehicle can realize intelligent control. Although the article only gives a general scheme design for the intelligent control of toy electric cars, if the whole system is perfected, it can even be considered for use in cars in the future. Alarm, if the driver fails to respond in time, the car will automatically complete deceleration and other operations according to the system control. Or it can also be applied in some unmanned small vehicles, such as lunar exploration vehicles. Therefore, the scope of application of this system is relatively wide. Our research is not only limited to this point, but we still need to do a lot of work to improve the entire system to meet the needs of the market.

The above is an example of the design scheme of the smart toy electric car introduced by Shenzhen Zuchuang Microelectronics Co., Ltd. for you. If you have bluetooth headset design needs, you can trust us. We represent a variety of single-chip microcomputers, voice chips, dual-mode Bluetooth ICs, and wifi chips. Brands include Songhan MCU, Yingguang MCU, Jerry Bluetooth, Ankai Bluetooth, Allwinner, and Realtek. Our technical services include: PCB design, MCU development, Bluetooth solution, software and hardware custom development, APP development, small program development, WeChat official account development, etc. It can also undertake the design of intelligent electronic products, the development of living appliances, the research and development of beauty equipment, the application of Internet of things platform, the smart home control system, the development of TWS earphones, Bluetooth earphone speakers, the development of children's educational toys, the design of electronic education products, etc.