ESP32 Forum

I use "Espressif IoT Development Framework. Official development framework for ESP32", i2s bck and ws is ok,but
my adc need mclk,how can i open esp32 mclk? (stm32 cpu i2s include mclk, bck, ws ) thank you.

We do not have a separate mclk output from the i2S driver, sorry. If your I2S codec is happy with a non-synchronized mclk (which a fair few are, in my experience) you can generate this using e.g. the LED PWM module.

The LED PWM module cannot be used to generate the MCLK required for I2S. MCLK requires at a rate of 64x to 256x of the sampling rate. The max. frequency that can be generated by this module is 78.125KHz (= 80MHz / 1024), so, don't try to make use of it. I want to take a look at PWM0~3 modules for generating the MCLK, but there is no information about them.

Colman

That's not entirely true. The hardware happily supports a divider of e.g. 2, leading to a 40MHz signal. The driver actually also supports this, but not in an obvious way: the led_timer_bit_t structure you use to select the depth only has 10 to 15-bit options. However, if instead you feed a literal '1' into the setup function instead of one of the enum values, it should work just fine to give you an 1-bit counter. The same goes for any other literal number in the 1-20 range. I'm not sure why we did not include the other bit options as well, to be honest.

Yes, you are right.

Regards,
Colman