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I2S DAC GPIO Pins on P5

PostPosted: 09 Aug 2014, 21:51
by jonclancy
Hi folks,

This thread is to confirm what P5 connector GPIO pins are allocated for I2S DACs in Rune, and to allow Google searchers to find the info quickly.

I am borrowing heavily on the posts Ian (IDM) made on the Volumio forums, as we're both using the Pi with a Philips TDA1541A DAC.

Ian said:

For the I2S connection I have taken:
LRCK from pin 4 of the Pi's P5 and connected it to Pin 1 of the TDA DAC
BCK from pin 3 of the Pi's P5 and connected it to pin 2 of the TDA DAC
Data from pin 6 of the pi's P5 and connected it to pin3 of the TDA DAC
Ground from pin 8 of the Pi's p5 is taken to digital ground of the DAC chip

Pin 4 of the DAC chip is connected to pin2 (BCK) of the Dac chip.

I'm looking to use I2S into my Pedja Rogic AYA DAC. I'm going to try injecting the I2S in upstream of resistors R106-R108 (SDATA, WS, BCK). There is a reclocker onboard this DAC.

Please may I confirm which P5 pins correspond to which in Rune?

Here's a graphic for any Googlers: ... p5-header/

Many thanks!!!


PS - Bright Idea I had - can I use a Pi to connect via a VPN to my Router at home, so I can stream my NAS tunes while I am away? This would make for great listening while on holiday etc! I guess I would need a static IP from my ISP.

Re: I2S DAC GPIO Pins on P5

PostPosted: 09 Aug 2014, 22:17
by jonclancy
Found this:

Raspberry Pi Header Pins: Mbed CODEC board:

P1-03 —– SDIN (i2c data)

P1-05 —– SCLK (i2c clock)

P5-02 —– 3.3V

P5-03 —– BCLK (bit clock in)

P5-04 —– LRCIN (frame sync clock in)

P5-06 —– DIN (i2s data in)

P5-08 —– GND

Here: ... pberry-pi/

Thanks pasdesignal!

Re: I2S DAC GPIO Pins on P5

PostPosted: 10 Aug 2014, 19:11
by jonclancy
A bit of research tells me the GPIO listed are good for the RaspyPlay3

Like Ian, I am experiencing static on the output. I've just resoldered directly to the DAC chip pins, rather than upstream of my reclocker.

OK, I have music, but with a background crackle. Very near, I think....

To be continued.

Re: I2S DAC GPIO Pins on P5

PostPosted: 10 Aug 2014, 21:27
by jonclancy
Sadly, no joy. I hot-swapped the wires and with them directly on the DAC pins I had the best result. Still sounds like someone is frying bacon in the background, though.

I haven't tried a different PSU for the Pi. Could be a load of noise coming through from this - it's my phone charger!! The Pi showed output on WS, BCK and DATA on my scope, so all is well there. IIRC, it was 1.4xxx MHz frequency.

Any comments gratefully received!