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RP2040 Software Design

Hardware to Interface

  • TI TAA3040 - 4 channel audio ADC
    • SPI or I2C control interface
    • TDM audio sample output
  • some stereo DAC - probably another TI part with TDM or I2S input
  • USB interface to present device as input and output channels to a host computer

4-Channel ADC samples in via TDM Interface

First pass of the PIO program was written, intending to test with another pico providing the TDM output signal

  • PIO program to receive samples on serial pin as a slave to the TAA3040 ADC providing bit clock and sync pulse
  • one 32-bit sample will be pushed to the RX_FIFO at a time, one sample from each channel per TDM frame

ADC control and configuration via SPI or I2C

There are a lot of features on the TAA3040 that are configurable by software. For a first pass, just set the chip up in a static configuration and let it go. For future improvement, there are a ton of ways it could be set up and integrated with the USB audio specification.

2-Channel stereo output to DAC via I2S or TDM


USB Audio interface

transmit 4 channels of samples to the host, and receive 2 channels back from the host. Also handle configuration - there are a ton of things that could be exposed to the USB host as configurable options and it would be cool to support a lot.


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