Introduction to Bluetooth Module

The Bluetooth module is a commonly used wireless communication module, which is widely used in various types of smart devices. The wireless bluetooth module refers to the basic circuit set of chips integrated with bluetooth function, which is used for short-range 2.4G wireless communication module.

For the end user, the Bluetooth module is a semi-finished product. Through the process of functional redevelopment and encapsulation on the basis of the module, the final product that can utilize Bluetooth communication is realized. The Bluetooth low energy module (BLE) refers to a module that supports Bluetooth protocol 4.0 or higher, also known as a BLE module.

Bluetooth versions include V1.0, V2.0, V3.0, V4.0, the latest is V4.0, and Bluetooth is backward compatible. For example, mobile phones with V2.0 cannot search for modules that recognize Bluetooth 3.0, and vice versa Can.

Because Apple devices have special settings for Bluetooth devices, the Bluetooth serial port module before V4.0 cannot be directly applied to Apple. If the friends who use Apple encounter the situation that the pairing of the mobile phone and the Bluetooth module is unsuccessful, you can try to search for LightBlue in the app store. As for the use of LightBlue, the editor is not very clear. If you need it, you can explore it (or Also buy an Android one~).

Operating mode

The Bluetooth module has two working modes:

Command-response working mode and auto-connect working mode.
When the module is in the automatic connection working mode, it will automatically transmit the data connected according to the pre-set method; when the module is in the command response working mode, it can execute AT commands, and the user can send various AT commands to the module to set the control for the module. parameters or issue control commands.

The AT command can only take effect when the module is not connected. Once the Bluetooth module is connected to the device, the Bluetooth module will enter the data transparent transmission mode (the AT command is the command applied to the connection and communication between the terminal device and the PC application, AT That is Attention. The AT command is a string that starts with AT and ends with a character. The response data of the AT command is included in it. Each command is executed successfully or not, there is a corresponding return.)

The Bluetooth AT command sets corresponding to different Bluetooth modules are different. Generally, there are corresponding AT command sets in the Chinese data manual of the Bluetooth module provided by the seller.

Connect the bluetooth module to the RXD, TXD, GND, VCC of the usb to ttl, press and hold the small button on the bluetooth module, and then power on (press and hold the power on to configure the mode, and power on directly is the normal use mode), Using the Bluetooth test software, let the module enter the absolute AT mode, get the module information, and get the information of the Bluetooth module.
Usually configure baud rate, master and slave, pairing password, you can set module parameters, set device name, connection password, etc. Make sure that the baud rate is the same, otherwise there will be garbled codes and the information exchange between them will not be successful.

The Bluetooth module can be used as a full-duplex serial port without knowing the complicated Bluetooth protocol.

Just like connecting to the conversion module, the RX of the Bluetooth module is connected to the TX of the microcontroller, the TX of the Bluetooth module is connected to the RX of the microcontroller, and the VCC and GND pins are connected, and other pins are usually ignored.

Chengzhitai Technology Co., Ltd. was established in 2014.Chengzhitai is specialized in the agent distribution of 2G, 3G, 4G, 5g, Nb IOT, WiFi Bluetooth and other modules.A large number of commonly used wireless modules are available in stock.

"Shenzhen chengzhitai Technology Co., wireless modules sold enjoy high market share and excellent market reputation among major consumer manufacturers.
For more information, please contact: 20U Yindu, Metropolis 100 Building, No.4, Zhonghang Road, Huaqiang North Street, Futian District, Shenzhen,China Telephone (+86)13723734515. Email: [email protected].