Raspberry Pi 1 Rev 2 and I2C DAC

[berneu65]

according to the Wiki, I2C DAC has to be wired to GPIO 18, 19 and 21. My Pi 1 R2 does not have the GPIO 19 and 21, and in minidexed,ini seems to be no way to define other pins. Is there any way to use a DAC?

[soyersoyer]

I haven't done this before, but these might help:
https://diyelectromusic.com/2021/11/21/raspberry-pi-i2s-audio-interface/
https://www.raspberrypi-spy.co.uk/2012/09/raspberry-pi-p5-header/
https://circle-rpi.readthedocs.io/en/50.1/devices/audio-devices.html#_CPPv419CI2SSoundBaseDevice

Circle recognizes the Pi model, so you don't need to modify the code, just connect the P5 header.
https://github.com/rsta2/circle/blob/5d819ab24f9a6c53ebab3525558051826b39d757/lib/sound/i2ssoundbasedevice.cpp#L345

[berneu65]

All Links are about I2S, not I2C, and the pins provided by the header are 28 to 31. I think this will not help.

[penfold42]

Which DAC are you looking to use?
GPIO 18,19,21 are used for I2S DAC on Raspberry Pis with 40 pin GPIO header.

The Pi1 rev2 with its 26 pin header requires you to connect to the usually unpopulated P5 header:
described here

Most cheap I2S DACs only need those 3 pins for the two clock and data signal.
Some DACs also need I2C to initialise them but this is only at startup - the audio data is still sent over the I2S pins.

[berneu65]

I have ordered a (not expensive) GY-PCM5102, wich seems to work over I2C.
I think its time for a new Raspi

[penfold42]

It's not I2C, it's I2S.

The links I and @soyersoyer provided apply to your setup.

[berneu65]

okay, but my soldering skills are limited, so I am afraid I would ruin the board. I think a newer Pi would be a better Solution, but thank you for your help