Jump to content
  • 0
IGNORED

Plug and play software / hardware volume control for piano 2.1 DAC?


Doron Behar

Question

So, today I run `amixer -c0` on my Raspberry Pi with Piano 2.1 DAC + Kali reclocker, and I saw this:
 

Simple mixer control 'Volume Ramp Down Rate',0
  Capabilities: enum
  Items: '1 sample/update' '2 samples/update' '4 samples/update' 'Immediate'
  Item0: '1 sample/update'
Simple mixer control 'Volume Ramp Down Step',0
  Capabilities: enum
  Items: '4dB/step' '2dB/step' '1dB/step' '0.5dB/step'
  Item0: '1dB/step'
Simple mixer control 'Volume Ramp Up Rate',0
  Capabilities: enum
  Items: '1 sample/update' '2 samples/update' '4 samples/update' 'Immediate'
  Item0: '1 sample/update'
Simple mixer control 'Volume Ramp Up Step',0
  Capabilities: enum
  Items: '4dB/step' '2dB/step' '1dB/step' '0.5dB/step'
  Item0: '1dB/step'

 
Which suggests that the hardware supports some kind of plug and play volume control that controls directly the card? Perhaps this feature is available via the spare GPIO pins?

 

P.S I wanted to post this question on allo's forum, but the website wouldn't let me do it from some reason.

Link to comment

4 answers to this question

Recommended Posts

  • 0

Thanks for the links @bluesman. I'm familiar with the concept of GPIO pins in Raspberry Pi. I don't understand something else: Here's what the datasheet for the Piano DAC is saying:

 

707662008_Screenshotfrom2020-09-1917-22-24.png.c78b9386c0f8ac7ac42e0ea3aa357cc9.png

 

So I guess I can go ahead and connect anything I want to pins 6,8,10,14,13? But pin 13 and 14 seem to be of special purpose - labeled SDZ_AMP and MUTE_AMP . Are pins 13 & 14 ready to be used directly, without software to setup? Is this what's counted as true "hardware volume control"? I'm pretty sure that connecting encoders to the other GPIO pins and writing a software daemon that will run `amixer` commands would not be considered a hardware based volume control.

 

P.S I don't use volumio - I'm trying to setup it up all by myself.

Link to comment

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


×
×
  • Create New...