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Maash
Posts: 31
Joined: Tue Aug 23, 2016 10:18 am

Re: I2S Success (at last) !

Tue Aug 22, 2017 11:50 am

Interestingly also my portaudio problems went away with new Kernel.
More like a comfyman...

shivasiddharth
Posts: 8
Joined: Thu Aug 24, 2017 12:05 pm

Re: I2S Success (at last) !

Thu Aug 24, 2017 12:08 pm

I have used the Google voice hat's device tree overlay to get the I2S mic and amp working.. here is the detailed post. Hope someone finds it useful. https://www.hackster.io/shiva-siddharth ... hat-9f96ca

czyskows
Posts: 40
Joined: Sun Oct 07, 2012 5:42 am

Re: I2S Success (at last) !

Sat Sep 02, 2017 4:10 am

Hi,

I'm trying to write a driver for an audio board with a CS42448 codec that uses the PLLD clock on the RPi. I've been through all the posts I can find on this issue, and none seem to point to ways to accomplish this. Most of the posts I've found point to deprecated kernels that don't use the bcm2835_i2s.c file to set clocks. If anyone is out there still checking in on this post, here are a couple questions that I hope are somewhat basic:

1. On current kernels (4.9.y) my suspicion is that the bcm2708_i2s module is no longer available and that you have to use the 2835_i2s module now. Is this correct?
2. Is it possible to set the I2S clocks using the 2835_i2s module? If so, does anyone have a hint as to how?
3. It seems that most of the people who were successful with I2S have used some sort of "loader" module that creates a link between the CPU and codec DAI streams. However, all of the boards in the repository (/sound/soc/bcm/) just use device tree overlays. I've been able to compile an overlay for my board, but it doesn't seem to link the two streams. Is a "loader" module necessary to do this?

Eternal gratitude to anyone who can help with these issues.

Cheers,
Colin

Mazerunner
Posts: 1
Joined: Sun Mar 04, 2018 6:26 pm

Re: I2S Success (at last) !

Sun Mar 04, 2018 6:40 pm

@ LisaJK
Hii
I happened to see your post and I'm working with the Knowles Mic on raspberry pi 3 .I've followed the adafruit I2S mems mic guide to set it up with my pi 3 ...I've loaded and compiled the kernel module driver with the following link guide including the wiring but my VU meter doesn't move from 00 when I run arecord and my Knowles Mic doesn't record anything,Also im using a USB port to power up my raspberry pi 3 do you think could be a factor of less power?.Can you please guide me on how you set up and if the link I'm following is accurate for the Knowles Mic .
https://learn.adafruit.com/adafruit-i2s ... g-and-test
God Bless you for the help!

DiegoCabral
Posts: 3
Joined: Tue Mar 13, 2018 11:51 am

Re: I2S Success (at last) !

Tue Mar 13, 2018 1:40 pm

Mazerunner wrote:
Sun Mar 04, 2018 6:40 pm
@ LisaJK
Hii
I happened to see your post and I'm working with the Knowles Mic on raspberry pi 3 .I've followed the adafruit I2S mems mic guide to set it up with my pi 3 ...I've loaded and compiled the kernel module driver with the following link guide including the wiring but my VU meter doesn't move from 00 when I run arecord and my Knowles Mic doesn't record anything,Also im using a USB port to power up my raspberry pi 3 do you think could be a factor of less power?.Can you please guide me on how you set up and if the link I'm following is accurate for the Knowles Mic .
https://learn.adafruit.com/adafruit-i2s ... g-and-test
God Bless you for the help!
@Mazerunner, first get a good power supply 5V with at least 2A output to provide power via mini-usb, this is a main problem for many Pi communication. Have you checked if the module is installed and running? enabled I2S on the config.txt? All your setup following step by step the tutorial you've mentioned on adafruit should give you SCLK on pin 18, FS/WS on pin 19 and SD on pin 20, please check all the steps on terminal to see if ther is any error. Do you have an oscilloscope to check those pins?

Cronus99
Posts: 4
Joined: Wed Aug 15, 2018 9:15 pm
Location: India

Re: I2S Success (at last) !

Fri Sep 21, 2018 7:14 pm

Hi,

I have been trying to set up i2s on my raspberry pi 3 model B as well, with no luck. I followed this adafruit guide: https://learn.adafruit.com/adafruit-i2s ... g-and-test

Right now these are the waveforms im getting while running $ arecord -D plughw:1 -c2 -r 48000 -f S32_LE -t wav -V stereo -v file_stereo.wav

1. LRCLK (BCM 19, pin 35)



2. BCLK (BCM 18, pin 12):



LRCLK seems to look fine (oddly shaped though), but BCLK looks like a small signal triangle wave? I have tried changing power supplies as well, but it was the same everytime. Could anyone take a look and shed some light on this?
Attachments
lrclk.gif
lrclk.gif (96.49 KiB) Viewed 103 times
bclk.gif
bclk.gif (78.04 KiB) Viewed 103 times

HiassofT
Posts: 105
Joined: Fri Jun 30, 2017 10:07 pm

Re: I2S Success (at last) !

Sat Sep 22, 2018 7:08 am

Are you maybe using a DSO 138 or a similar toy to check the signals? If yes the result is expected, bclk will be about 3MHz and the DSO 138 has a maximum bandwidth of 200kHz.

so long,

Hias

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