I want to build a Openwrt based digital audio processor on AR9331 soc. Stereo audio input will be taken from I2S MICIN and output will be send to I2S SD pin. One kernel module has to be used for  I2S and user space application will handle all DSP routine. On receive of audio sample kernel module will send a interrupt signal to user space and user app will read this sample from kernel space, execute all DSP algo in the ISR and send modified audio sample data to back kernel space.

One I2S DAC codec will be connected to soc  I2S SD & ADC codec to  soc 2S MICIN. Soc will generate I2S MCK & I2S CK signal to supply clock to ADC & DAC.

Following DSP algorithm may be implemented.

Delay pedal.
Echo pedal.
Reverb pedal.
Metronome.
Tremolo.
Chorus/Vibrato.

Please somebody help for implementation of the project.

/jags

Hi Jagspaul, this looks like interesting but also very demanding project. What are your plans for this project? Which part is your domain of expertise?

AFAIK there is no I2S module (driver) for AR9331 so first step is to write and release this module as open source. I know that there are people who have written I2S modul but they kept it closed source

https://github.com/franzflasch/ar9331-i2s-alsa
http://www.8devices.com/community/viewt … 3701#p3701

(Last edited by pepe2k on 28 Apr 2015, 08:12)

Hello Valentt,
My plan is to make this project open source. I have some experience on arduino based reverb project.
I have got I2S code at Git (https://github.com/franzflasch/ar9331-i2s-alsa). Now I need help how to use this code as per my requirment (described at my topic). How can you help me??

/jags

(Last edited by jagspaul on 2 May 2015, 08:09)

I have gone through i2s code (https://github.com/franzflasch/ar9331-i2s-alsa) . It is quite complex to me to understand every step. However I have tried to know how to read/write audio sample to i2s but no success. Is there anybody can help me in this regards?

/jags

I wanted to access i2s port without using alsa-lib. That is why I need to know how to read/write audio sample to i2s is done and how to make a interface to my user space app of the above said i2s-alsa module.

Waiting for some positive responce.

/jags

(Last edited by jagspaul on 2 May 2015, 08:14)

https://github.com/GBert/railroad/tree/ … er-poc-ath

This is a very interesting project, AFAICT. Unfortunately, I have no idea what packages are needed to provide the features besides the Linux kernel driver. Will carambola package be enough?

BTW, do you already have a hardware platform? If not, perhaps this AirMusic discussion thread will probably be a good candidate platform.

Has there been some progress with this project?