Bc04_ B demonstration board MCU Communication Problems

The newly purchased bc04_ B demonstration board communicates with the mobile phone via serial port Bluetooth, And the sending and receiving are correct.

MCU Communication baud rate 9600

Connect the serial port of the single-chip microcomputer to the RS232 serial port of the Bluetooth demonstration board. After Bluetooth is enabled, the Bluetooth connection automatically disconnects the transmission data.

Analysis: The study found that the Bluetooth demonstration Board uses miniusb power supply and the Single-Chip Microcomputer Development Board is also USB power supply. Two USB power supply ports may have poor voltage, resulting in two devices not sharing the ground.

Connect the VCC Gnd on the base station Board separately to power the bluetooth module. It is found that the Bluetooth will not be automatically disconnected. However, data transmission is abnormal.

Then, the single chip microcomputer Tx, RX separately lead to connect to the bluetooth module Tx, dx, And suddenly found that there is a correct data transmission.

The Bluetooth module and serial port conversion chip are max3221 Single Chip Microcomputer serial port conversion chip is maxcompute. It is estimated that the communication between the MCU and the bluetooth module is abnormal due to an unknown communication problem between the two chips.