Raspberry Pi Pico S/PDIF receiver library
Overview
- S/PDIF receiver by rp2040 PIO function
- format: 2ch, 16bit or 24bit
- sampling frequency: 44.1 KHz, 48.0 KHz, 88.2 KHz, 96.0 KHz, 176.4 KHz, 192.0 KHz
- signal detecting function for all supported sampling frequencies
Supported Board and Peripheral Devices
- Raspberry Pi Pico (rp2040)
- S/PDIF Coaxial or TOSLINK Rx module (DLR1160 or equivalent)
Pin Assignment & Connection
S/PDIF Rx
| Pico Pin # | GPIO | Function | Connection |
|---|---|---|---|
| 20 | GP15 | DATA | from S/PDIF data |
Notes:
- 74HC04 should be genuine device, otherwise (counterfeit device) it could not work at higher sampling frequencies.
- if TOSLINK only, direct connection from module output to GP15 will work as well.
How to build
- See "Getting started with Raspberry Pi Pico"
- Put "pico-sdk", "pico-examples" and "pico-extras" on the same level with this project folder.
- Set environmental variables for PICO_SDK_PATH, PICO_EXTRAS_PATH and PICO_EXAMPLES_PATH
- Confirmed with Pico SDK 2.0.0
> git clone -b 2.0.0 https://github.com/raspberrypi/pico-sdk.git > cd pico-sdk > git submodule update -i > cd .. > git clone -b sdk-2.0.0 https://github.com/raspberrypi/pico-examples.git > > git clone -b sdk-2.0.0 https://github.com/raspberrypi/pico-extras.git > > git clone -b main https://github.com/elehobica/pico_spdif_rx.gitWindows
- Build is confirmed with Developer Command Prompt for VS 2022 and Visual Studio Code on Windows environment
- Confirmed with cmake-3.27.2-windows-x86_64 and gcc-arm-none-eabi-10.3-2021.10-win32
- Lanuch "Developer Command Prompt for VS 2022"
> cd pico_spdif_rx\samples\xxxxx # sample project directory > mkdir build && cd build > cmake -G "NMake Makefiles" .. > nmake - Put "xxxxx.uf2" on RPI-RP2 drive
Linux
- Build is confirmed with pico-sdk-dev-docker:sdk-2.0.0-1.0.0
- Confirmed with cmake-3.22.1 and arm-none-eabi-gcc (15:10.3-2021.07-4) 10.3.1
$ cd pico_spdif_rx/samples/xxxxx # sample project directory $ mkdir build && cd build $ cmake .. $ make -j4 - Download "xxxxx.uf2" on RPI-RP2 drive
Decode output format
- 32bit output for each S/PDIF sub frame including header, audio data, AUX, VUCP
- see comments in spdif_rx.pio for further detail
Sample projects
detect_samp_freq
- display sampling frequency, C bits of S/PDIF frame and number of parity errors while decoding
spdif_to_i2s_32b
- convert S/PDIF input to I2S 32bit output