Page 1 of 1

USB Audio, volume control using Teensy?

Posted: Mon Jun 13, 2016 5:46 am
by drlbradley
Might be over thinking this but...

Am using a C-Media USB Audio to get sound out of the Pi, and am wondering how best to control the volume output.
Anyone doing this and using the Teensy keyboard HID to read volume +/- from buttons, or from a pot or rotary encoder?

I found someone doing something similar here https://deskthority.net/workshop-f7/vol ... 11764.html

Re: USB Audio, volume control using Teensy?

Posted: Mon Jun 13, 2016 6:45 am
by drlbradley
More thoughts on this:

1/I could just have two additional buttons , perhaps mapped as keyboard chars in the Teensy code, which I then assign in the retropie config as volume up/down.

2/ Or just define hotkey combo to do volume up/down

input_enable_hotkey_btn = 8 #Select
input_volume_up_axis = +1 #Up on Joystick
input_volume_down_axis = -1 #Down on Joystick
input_audio_mute_axis = +0 #Left on Joystick

3/ or add one hardware button, used as the hotkey button and then hotkeys defines as in 2/

my favored option would still be two used a potentiometer, in the original case location, to drive the volume..

help!

Re: USB Audio, volume control using Teensy?

Posted: Mon Jun 13, 2016 7:16 am
by Fleder
You could also buy another DAC which already has got volume control.
Like this or this.
Not sure if the last one works on linux, though.