I am working on a project that uses a prebuilt bluetooth speaker module. Originally I was going to use an arduino to just fire a relay that would turn the module on and off, but I was wondering if anyone knew if it would be possible to use transistors to adjust the speaker volume using PWM in the same way you would for an LED strip?
It looks like that kit would only adjust volume (amplification) via the Bluetooth protocol. I don’t see any provisions for physical volume control. So your phone volume would control the speaker volume. Are you trying to bypass that and add physical “local” volume?
That is correct. You could probably use transistors if you want and have one microcontroller control another… Not really sure your end goal - keep in mind that a phone linked via BT will already have direct control over the audio; and this can still allow for “local” control. I have two of these modules wired inside of OEM car stereos to add a bluetooth “line in”.
I have ordered two for testing.
My end goal is actually a birthday present for my sister, a speaker system that can connect to the TV in her bedroom and also to the bluetooth module.
I am a little confused as to why I would use transistors and not just an arduino digital pin (with a common ground)?