Need help understanding volume controls on a bluetooth board.

[Jack.Straw]

Hello. I've been playing around with this bluetooth speaker project. The bluetooth module i've chosen is **broken link removed**. I tested the basic usage last night and it worked great, and I like that it has an audio input for when i want to connect a music device that doesn't have bluetooth. I'd like to explore putting a volume control on the case, and maybe even forward, back, and play/pause buttons. The module seems to support this with its many solder points, but i'm not exactly sure how to use them. Here is a picture of the module that shows the solder points and what they do:



At first i thought that the volume + and - were where i would connect a potentiometer, but on further reflection i'm thinking maybe that's not the case. I'm thinking they volume + and volume - are not positive and negative, but rather volume up and down, and likely work in the same way the play, next, and back options do. The problem is, i don't know how any of it works. If i had to make a guess, i would say that i would put a simple button that briefly connects the one of the control pins to the one labeled "key_com." I could test this by touching one end of a wire to the vol+ location, and then briefly touching the other end of the wire to the key_com location and see if the volume increases. But, i'm afraid of doing anything that might fry something in the circuit so I thought i would come here and ask. I did contact the seller and he sent me the only information he had, which was all in Chinese. I used an image translator to identify and translate the text, but it wasn't helpful. For the key_com it just says "KEY port 0 is a common end."

If this module works the same way a lot of bluetooth speakers i've used does, using the volume + and - pins on the board will likely change the volume on my device (phone) just like i had used the volume buttons or slider on the device itself. I may opt for a potentiometer anyway because the volume of the amp is pretty loud with my phone on its lowest possible volume. Going more than half way on my phone's volume is too loud.

Thanks for any advice you can offer!

 

[KlausST]

Hi,

I think it´s quite obvious. You just need to connect five keys. Pushbutton, normally open.
VOL+ --> key --> KEY_COM
VOL- --> key --> KEY_COM
PLAY --> key --> KEY_COM
NEXT --> key --> KEY_COM
BACK --> key --> KEY_COM

Klaus

 

[Jack.Straw]

Ok, so my guess was correct. Thanks for the confirmation! I appreciate it!

 

[Nizar_Ib]

All what you need to do is to open the datasheet of the Audio Receiver chip on your board and look at the pins description of it, then see how things works.

 

[Jack.Straw]

All what you need to do is to open the datasheet of the Audio Receiver chip on your board and look at the pins description of it, then see how things works.

Nizar, this is the only thing i could find on this board and I don't know what chip it uses. I used an image translator on it and was able to get a lot of info, but it wasn't clear to me which pins to connect the controls to so i asked here. I was guessing it was the key_com, but without any experience i wanted to ask before doing anything that might potentially damage the board.

 

[Nizar_Ib]

can you look at the biggest components on the board and read the OPN there? you can make a picture and upload it to here so maybe we can help you.

 

[Jack.Straw]

can you look at the biggest components on the board and read the OPN there? you can make a picture and upload it to here so maybe we can help you.

Thanks Nizar, but at this point i've gotten it figured out thanks to Klaus' confirmation. I've tested the functions with a bit of wire and everything works great. Thanks!