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enable i2s interface on Rpi p3 or p2

Posted: Wed Mar 30, 2016 8:43 pm
by Dobi
Hi everyone,

please give me information what should I do to activate the i2s Interface on Rpi p3 or p2?
thank you very much!

Dobi

Re: enable i2s interface on Rpi p3 or p2

Posted: Thu Mar 31, 2016 5:43 pm
by rkn
Is this possible at all?

From http://elinux.org/RPi_Low-level_peripherals:
It is also possible to reconfigure GPIO connector pins P1-12 and 13 (chipset GPIO 18 and 21) to provide an I2S (a hardware modification may be required[16]) or PCM interface.[17] However, PCM_FS and PCM_DIN (chipset pins 19 and 20) are needed for I2S or PCM.
From the moderator post at viewtopic.php?f=63&t=2631:
Moderator: this is an old thread! Since revision 2 the PI has a new header P5 which has I2S.
But, even revision 2 is pretty old now. Did I2S disappear somewhere along the line?

The schematics for the Pi 3 also haven't been posted, nor could I find a data sheet for the new Broadcom chip.

Anyone know if it's available?

Re: enable i2s interface on Rpi p3 or p2

Posted: Thu Mar 31, 2016 6:08 pm
by rpdom
I think so

http://pinout.xyz/pinout/pcm

The chip capabilities haven't changed in that respect.

Re: enable i2s interface on Rpi p3 or p2

Posted: Fri Apr 01, 2016 2:56 pm
by Dobi
Hi

Thank you very much!

The schematic for the 40 pin header with the CLK, Data and FS signal pins is very helpful.

But on the i2s pins (CLK, Data and FS) is no signal measureable with a oscillocope.

I try to find a very simple way to enable the PCM singals to the I2S (CLK, Data, FS) pins.

I try it with following insturction in the /boot/config.txt file:

dtparam=i2s=on

But it does'nt help alone. There is still no signal measureable on I2S (CLK,Data,FS) pins.

I there anything else that have to be configured?

br Dobi

Re: enable i2s interface on Rpi p3 or p2

Posted: Fri Apr 01, 2016 3:20 pm
by PeterO
You also need a device tree entry for a sound card that actually uses I2S inorder for the hardware to be enabled and programmed.

PeterO