Control external attenuator with SB3 remote

[Claus-DK]

I would like to make an audio volume relay attenuator controlled from the SB3 remote control.


First step is to find out if using the volume control changes signal level from the DAC in SB3.

If the signal level from the DAC isn't changed I expect to use the analog output directly from the DAC feeding the attenuator through a buffer circuit.

If the signal level from the DAC is changed I see no other way than to use the SPDIF output alternatively find the I2C inside the SB3 to feed an external DAC.

Can any of you help me with information to help me further with this?


In order to find a digital signal within the SB3 that I can use to control my attenuator and perhaps to find the I2C signal before the DAC it would be of great help with schematics or perhaps a photo. Can any of you help me wit this?


Regards
Claus

[Mathiou]

I am not sure that I completely understand what you want to do but let me tell you how it works with my SB:

- My Squeezebox is connected to a home-made preamplifier
- The volume buttons on the SB remote changes the volume of the preamplifier
- There is a small plugin in Slimserver to lock the volume when the SB receives the "volume-up" or "volume-down" from the remote

The IR receiver in my home-made preamplifier is visible here:
http://www.lextronic.fr/Comfile/telecom.htm

It works with a specific remote control but it also works with the SB remote !!! (But it is strange because this specific remote does not control the SB so I guess IR codes are not exactly the same)

When the receiver receives an IR code, it sends a value (serial transmission) related to the button pressed. With a micro-controller, you get this value and do what you have to do after...

I hope it can help you !