Raspberry 5 audio I2S mechanism using PIO
Budget: $250 – $750 USD
The project is to port a I2S mechanism implemented using PIO on Raspberry PICO to Raspberry 5 that also has this PIO peripherals.
The Pico github project is here https://github.com/malacalypse/rp2040_i2s_example There is also:
- a discussion around I2S and PIO with reference to the Pico project from the link above https://forums.raspberrypi.com/viewtopic.php?t=337270
- a valuable resource on PIO on the target RPi5 although it does not cove specifically the I2S but may help and speed up the porting https://github.com/G33KatWork/RP1-Reverse-Engineering/ with some supplement here https://github.com/MichaelBell/rp1-hacking/
The project should allow to handle this I2S PIO mechanism using possibly built-in ALSA buffering functionality. A simple concept like using the DMA that is also part of the Pico project to feed ALSA buffers would be enough [if DMA can work with PIO].
My preferred idea is to test the project with sound playback, e.g. simple file player to ALSA/Pulse Audio buffers that are played out by I2S PIO (then converted to standard SPDIF by using a simple external converter)
Please describe in the bid what approach to ALSA<>PIO integration would you recommend from your experience ?
PIO is a very specific highly configurable hardware mechanism so the contractor should possibly have practical experience with PIO or similar hardware.
The initial assumption is the project be set up in VSC but contractor's suggestions are much appreciated.
The Pico github project is here https://github.com/malacalypse/rp2040_i2s_example There is also:
- a discussion around I2S and PIO with reference to the Pico project from the link above https://forums.raspberrypi.com/viewtopic.php?t=337270
- a valuable resource on PIO on the target RPi5 although it does not cove specifically the I2S but may help and speed up the porting https://github.com/G33KatWork/RP1-Reverse-Engineering/ with some supplement here https://github.com/MichaelBell/rp1-hacking/
The project should allow to handle this I2S PIO mechanism using possibly built-in ALSA buffering functionality. A simple concept like using the DMA that is also part of the Pico project to feed ALSA buffers would be enough [if DMA can work with PIO].
My preferred idea is to test the project with sound playback, e.g. simple file player to ALSA/Pulse Audio buffers that are played out by I2S PIO (then converted to standard SPDIF by using a simple external converter)
Please describe in the bid what approach to ALSA<>PIO integration would you recommend from your experience ?
PIO is a very specific highly configurable hardware mechanism so the contractor should possibly have practical experience with PIO or similar hardware.
The initial assumption is the project be set up in VSC but contractor's suggestions are much appreciated.