Hi,
I'm using the DAC+ ADC for a project, but I really only need the ADC. Is there a way to turn off the DAC? I've tried bending the power pins (AVDD, DVDD, CPVDD and LDO0) up to disconnect the whole IC, but then my Pi Zero doesn't recognize the board anymore. In dmesg I get:
snd-rpi-hifiberry-dacplusadc soc:sound: ASoC: failed to init link HiFiBerry DAC+ADC: -517
No, that's not possible. Doing this you simply destroyed your DAC+ ADC.
Well I've bend them back and it works fine again.
Do you now if I could change anything in the kernel drivers and/or device tree to set the RQPD bit in Register 2, Page 0? That should power down the DAC
Why would you do this? There is no need for this. Just simply don't use the DAC if you don't need it.
In a quite special application, we have a fairly sensitive amp in front of the ADC that picks up noise which we suspect comes from the charge pump in the DAC. As we dont use the DAC we want to disable it.
The whole board won't work without the DAC. It's not possible.
BTW: It's quite unlikely that the DAC charge pump is the problem here. The Pi itself probably creates much more emissions.
We only receive the noise while the soundcard is recording.
Can you give some insight as to why it is impossible? With the slave mode enabled (https://github.com/raspberrypi/firmware/blob/master/boot/overlays/README#L1182), shouldn't it theoretically work?
The whole board is designed to work as it is. You would need a completely different driver for this and probably even hardware modifications.
We can support you with this, but this would be an engineering service that we would charge by the hour.
If you're interested, you can contact us at support@hifiberry.com.
Just note, that this won't be only a few hours of work!
Thank you for the help and the offer, but we're not interested in that.