Almost all Bluetooth products have MCU's, but How To Make Communication Between the MCU and the Bluetooth Module? Today you would learn about how.

Taking the BT906 as an example:

1.Connect the MCU and the Bluetooth module properly.
Usually you may know that just need use UART (TX /RX) then can communicated .
Your MCU TX connected to BT906 module's RX.Please checked if you already do like this ?
If you have confirmed that there are no circuit problems,then we go to step 2

2. Make sure the Hardware Part  is okay.
1)Connect the TX RX of the module to the computer through the 3.3V USB Transfer to Serial Port 
2)Open ''Feasycom Serial Port '',choose the related port ,Baurd Rate :115200 ,Choose :New Line 
3) Send ''AT+VER '' ,If there is a respond :+VER=xxxxx,then it means hardware it is okay .

3.Make sure the software part is okay.
1)Send ''AT+MODE=2  ,then it will change into hid mode 
2)Use cellphone connected to hid device named Feasycom 
3)Open txt file to select the cursor 
4)Send hexadecimal          
             
 41 54 2B 48 49 44 53 45 4E 44 3D 32 2C 00 04 0D 0A. Then cellphone will received:  a
A  T  + H  I  D  S  E N D  =  2 ,       \r \n
                                00: ''control key'' value
                                04: ''hid value'' of '' a ''
                                                                                                                       
For more details about how to get bluetooth module communication with MCU,just feel free to contact feasycom team

Want to know how to upgrade the firmware of the MCU wirelessly? Please visit here: https://www.feasycom.com/how-to-upgrade-mcus-firmware-wirelessly.html