<alp/i2s.h> — I²S / SAI

Raw I²S / SAI bus access. For higher-level audio capture and playback, use <alp/audio.h>.

Header

#include <alp/i2s.h>

Quick example

alp_i2s_t *i2s = alp_i2s_open(&(alp_i2s_config_t){
    .bus_id         = ALP_E1M_I2S0,
    .sample_rate_hz = 44100,
    .word_bits      = 16,
    .channels       = 2,
    .format         = ALP_I2S_FMT_I2S,
    .direction      = ALP_I2S_DIR_TX,
    .block_frames   = 256,
});

alp_i2s_start(i2s);
alp_i2s_write(i2s, pcm_buffer, pcm_bytes, /* timeout_ms */ 100);
alp_i2s_stop(i2s);
alp_i2s_close(i2s);

Default-initialiser macro

alp_i2s_config_t cfg = ALP_I2S_CONFIG_DEFAULT(ALP_E1M_I2S0);
cfg.direction = ALP_I2S_DIR_TX;

ALP_I2S_CONFIG_DEFAULT(id) (v0.10) sets bus_id from id plus: sample_rate_hz = 48000, word_bits = 16, channels = 2 (stereo), format = ALP_I2S_FMT_I2S, direction = ALP_I2S_DIR_RX, block_frames = 256.

See the shared macro contract for the C++ compound-literal caveat that applies to every ALP_*_CONFIG_DEFAULT.

See also

• <alp/audio.h> — high-level audio
• Examples: i2s-tone