iotta codec-board audio IO — ES8311 DAC + ES7210 mic-array ADC over a shared full-duplex I2S bus (esp_codec_dev). Optional Build-B voice backend for the iotta device SDK; wire via Esp32Platform::set_audio().
iotta Opus voice codec — libopus (xiph/opus pinned by commit sha) plus the shared iotta make_opus_encoder/decoder factories. Optional: only needed by firmwares that enable the voice path (CONFIG_IOTTA_ENABLE_VOICE).