Inter-IC Sound (I2S) Bus

Overview

The I2S (Inter-IC Sound) API provides support for the standard I2S interface as well as common non-standard extensions such as PCM Short/Long Frame Sync and Left/Right Justified Data Formats.

Shell

When CONFIG_I2S_SHELL is enabled, an i2s shell command is available to stream a generated sine test tone over any I2S controller without writing application code. It is transport only; pair it with the codec shell to route the audio through a codec.

The tone commands are grouped under i2s tone:

  • i2s tone start <device> [frequency_hz] [sample_rate] [bits] starts a stereo test tone on the given I2S device. frequency_hz defaults to 440 Hz, sample_rate defaults to 48000 Hz, and bits defaults to 16 (valid values are 16, 24 and 32).

  • i2s tone stop stops the running tone.

  • i2s tone info shows the current tone stream status.

For example, to stream a 1 kHz, 48 kHz, 16-bit tone:

uart:~$ i2s tone start i2s@0 1000 48000 16
Streaming 1000 Hz tone on i2s@0 @ 48000 Hz, 16-bit stereo
uart:~$ i2s tone info
state    : streaming
i2s dev  : i2s@0
tone     : 1000 Hz
rate     : 48000 Hz
format   : 16-bit stereo, 64-frame blocks x 8
uart:~$ i2s tone stop
Stopped

The TX buffering used by the shell is controlled by CONFIG_I2S_SHELL_BLOCK_FRAMES and CONFIG_I2S_SHELL_BLOCK_COUNT.

Configuration Options

Related configuration options:

API Reference

I2S

Related code samples