Smart Bracelet Bluetooth Module Design and Development

It was not until the release of Bluetooth 4.0 that low-power Bluetooth technology was associated with smart wearable devices. These have gradually evolved from the original era of Bluetooth headsets. Now smart wearable devices using Bluetooth technology have almost become a symbol of the younger generation. In fact, in our life, Bluetooth technology has quietly changed our study and life. We have become accustomed to connecting smartphones to car voice systems via Bluetooth, so that we can safely complete operations such as making or answering calls through car audio; at home, smartphones or PDAs can also be connected to smart set-top boxes via Bluetooth, so that Synchronize the pictures and video data in the smart device to the ultra-clear TV screen.

Bluetooth (bluetooth) is a wireless short-wave communication technology that works in the 2.4GHZ (ie ISM) frequency band, and is a large-capacity short-distance wireless digital communication technology standard. Bluetooth is an asynchronous full-duplex communication method, and its core technology is frequency hopping technology. Bluetooth communication must be carried out in accordance with the Bluetooth communication protocol. The Bluetooth protocol specification allows developers to develop interactive services and applications based on interoperable wireless modules and data communication protocols. interoperability.

1. Hardware circuit design of smart bracelet Bluetooth module

1.1 Introduction of HC-06 module

The HC-06 module is specially designed for intelligent wireless data transmission, adopts the BlueCore4-Ext chip of British CSR company, and follows the V2.0+EDR Bluetooth protocol. The Bluetooth module HM-06 supports multiple interfaces and supports the SPP Bluetooth serial port protocol. It has the advantages of small size, low cost and high sensitivity. It supports general AT commands, and a series of operations such as Bluetooth connection and data transmission can be realized with a very simple program.

1.2 Bluetooth module hardware circuit design

Nowadays, people basically carry their smart phones with them at any time. Smart bracelets, as smart wearable devices, can realize connection and data communication with mobile phones by using Bluetooth connection. Most of the smart bracelets on the market now also use Bluetooth. way to connect to the phone. Now every smart phone has a bluetooth module, and the universality of bluetooth can connect smart phones and other smart devices with bluetooth anytime and anywhere. As another communication method for smart phones, Bluetooth facilitates the development and use of portable smart devices.

In order to realize the function of Bluetooth transmission, it is necessary to know the Bluetooth pairing method. The Bluetooth chip is divided into host, slave, and master-slave integrated machine. The host can communicate with the slave, and the slave can also communicate with the host. However, the host and the host Communication is not possible, and the slave cannot communicate with the slave. This article uses the Bluetooth module of the smart terminal as the host, so the HC-06 slave module is used in the design of this article, so that the search and connection can be realized on the smart terminal. In this paper, the Bluetooth module is connected with the 51 single-chip microcomputer. The reason for choosing a single-chip microcomputer is that the operation is convenient and the corresponding functions can be completed through a simple program. The Bluetooth module transmits data through the serial port, so the UART_TXD and UART_RXD of the Bluetooth module should be connected to the serial port of the microcontroller. The 51 single-chip microcomputer also has a serial port interrupt, so it is easier and more convenient to complete data transmission.

2. Software Design of Smart Bracelet Bluetooth Module

The communication process between the smart bracelet and the smart phone is that after the smart phone and the smart bracelet establish a Bluetooth connection, Bluetooth communication can be performed to transmit the motion data recorded by the bracelet. The Bluetooth communication process between them is as follows: firstly, after the user connects the smart bracelet according to the above method, the smart bracelet actively transmits the data to the mobile phone, and then updates the data stored in the mobile phone according to the transmitted data and records them. time. In this process, when the collected data has been sent, the smart bracelet will clear the data stored in itself and stop the transmission, and then start recording new exercise data.

The software design in this paper uses C language and Keil for programming, and 51 series single-chip microcomputer for testing. Because HC-06 supports general AT commands, a series of operations can be performed on the Bluetooth module through the serial port interrupt of the microcontroller, and it is also convenient for better maintenance and update of the system. The software process starts with the master-slave pairing through the pairing code. If the pairing is not successful, it ends. Otherwise, it enters the serial port interrupt to establish a connection and send data in the serial port interrupt. Finally, it checks whether the data is sent. In between, use HC- 06 general AT commands.

3. Bluetooth module system test

This article uses proteus for simulation testing. Because the transmitted data is inconvenient to observe directly, eight LEDs are connected to the P1 port of the microcontroller to test whether the program is correct by turning on and off the LEDs. After sending data 0XFE from the slave end and receiving it from the master end, click Light up the corresponding LED lights, send data from the end to the master end, and store the data after the master end receives it.

Summarize

From the development of Bluetooth to the present, low-power Bluetooth technology has been associated with smart wearable devices. Now Bluetooth technology is widely used in portable smart devices, and our lives are also quietly changing under this ever-improving technology. The bluetooth module HC-06 integrated with the BlueCore4-Ext chip of the British CSR company is a bluetooth module specially designed for intelligent wireless data transmission, and follows the V2.0+EDR bluetooth protocol. The Bluetooth module HC-06 supports multiple interfaces and can be used in different occasions, and the HC-06 supports the SPP Bluetooth serial port protocol, which has the advantages of small size, low cost, and high sensitivity. In this paper, the Bluetooth module of the smart bracelet is used as the slave, and the smart phone is used as the host. Bluetooth communication between. If you want to apply it on the bracelet, you only need to write an Android program to search for the Bluetooth module connected to the bracelet on the mobile phone.

The above is the development example of the Bluetooth smart bracelet module introduced by Shenzhen Zuchuang Microelectronics Co., Ltd. for you. If you have bluetooth headset solution development 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, microcontroller development, Bluetooth solutions, 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.