VS1053b I2S output to Esp32

[lorenzo318]

Hi all

I am a little bit confused about how to connect the 1053b i2s output to an esp32 mcu.

I know the 1053b is only master with respect to i2s interface so I need to program my esp32 as a slave. The first question is about the master clock generated by the codec. Is it required for esp32? Maybe the BCLK, LROUT and SDATA are enough in my case?

Another question is related to software point of view. How to configure internal codec registers in order to work correctly.? I would 24kHz Pcm audio samples to be transmit to the esp32 I2s interface.

Could you please provide me suggestions?

Thanks in advance.

BR

[Panu]

Hi!

The VS1053 outputs 16 bits per sample. Can the ESP32 receive I2S frames that have only 2 x 16 bits?

-Panu

[lorenzo318]

Yes, it could.

The i2s driver configuration on the ESP32 side is the following:

const i2s_config_t i2s_config = {
.mode = static_cast<i2s_mode_t>(I2S_MODE_MASTER | I2S_MODE_RX),
.sample_rate = 16000,
.bits_per_sample = static_cast<i2s_bits_per_sample_t>(I2S_BITS_PER_SAMPLE_16BIT),
.channel_format = static_cast<i2s_channel_fmt_t>(I2S_CHANNEL_FMT_RIGHT_LEFT),
};

16kHz, I2S_BITS_PER_SAMPLE_16BIT, Stereo.

My doubts are related to the wire connection since I don't understand how to use the codec MCLK, and if I have to use ESP32 as a I2S_MODE_MASTER or I2S_MODE_SLAVE. I read somewhere that the VS1053b works as a master only, not slave.

Perhaps, what's the right way to configure registers in order to work with I2S interface in that configuration.

Thanks a lot again.

BR.

[Hannu]

VS1053 can be 48,96 or 192 kHz master. So configure ESP to to slave and expecting 16 bits samples. Then you need to write VS1053 I2S_CF I2S CF_ENA bit high and the samplerate bits to enable i2S out. You shouldn't need MCLK.

[lorenzo318]

Thanks a lot!

BR