If you haven’t read my first update of the MH-M18 module you can view it here.
In my last update, I decided to test out the MH-M18 Bluetooth Audio Receiver module that I received on a breadboard circuit.
I set up my breadboard circuit above where 12v from my power supply was converted to 5v. That 5v output was connected to the module, the GND pin was connected to the GND pin of the 5v linear regulator. Then I connected the Left, Right, and GND pins of the module to a aux cord breakout board. From there, I was able to easily connect an aux cable to my speaker. Here were the results:
The pairing process was quick and easy. As soon as I played music through my phone, the sound was outputted to my speaker. However, it originally wasn’t like this. When I originally tried to set up this circuit I received a lot of noise that made the stereo output unbearable to listen to even when no audio was outputted.
From the picture above, my oscilloscope disaplyed a ton of noise when connected to the left stereo output of the module.
Solution: Instead of connecting the stereo GND to the GND of the linear regulator, I connected it directly to the GND pin of the module.
As soon as I did this, there was practically no noise and the module worked well. If you’d like to setup this circuit on your end here are some circuit diagrams I prepared for an easy setup.
Hope all works well with your bluetooth stereo projects!