Mozzi basics with ESP32

[Aranis Das]

Looking to run the example codes with an esp32 and an 8 ohm speaker connected to the dac pin (25). I am really confused on how to output sound aswell. I just want to run the basic sketches provided for now and understand how the library works.

Thanks!

[Martin Gerken]

The ESP32 cannot drive a speaker directly (no MCU can do that); you need
an amplifier, i.e. those LM358 based modules from your favourite chinese
dealer. Better go for a DAC module with amplifier (and thus do not use
the ESP32-built-in DAC), like the MAX98357A.

Best, Martin

[Aranis Das]

Thanks for the response. I actually had one laying around. I used a tutorial that uses some math to get a square wave output.

Now my question is, how exactly can i output via i2s with mozzi? I have tried running the basic example (sinewave) but it seems that it needs more configuration.
 is there a guide on how to configure mozzi with i2s? I think the documentation only shows that it is supported, but i cant seem to find something with an example program.

Thanks again

Aranis

[tomco...@live.fr]

Hi,

Sorry for the delay.

Does the peculiar chip you are using is having an I2S dac onboard? Otherwise you will need an additionnal I2S DAC, connected to the ESP32 to make that mode work.

Best,

Tom

[Aranis Das]

no. i'm using a max98357. This should work but i still hear nothing.
Mozzi: Mozzi on ESP32-based boards. (sensorium.github.io)
the link above is what i got from the website. I am quite confused on how to approach this. Could you give a brief explanation?

Im guessing I would need to configure to "MOZZI_OUTPUT_I2S_DAC". 

[tomco...@live.fr]

Hi,

I do not experience with ESP32 but the link you gave is the correct approach normally.

If you are using Mozzi 2, you should add:

#define MOZZI_OUTPUT_I2S_DAC

#define MOZZI_I2S_PIN_BCK ... // (default: 26)

#define MOZZI_I2S_PIN_WS ... // (default: 15)

#define MOZZI_I2S_PIN_DATA ... // (default: 33)

(with the correct pin numbers w/r to how the DAC is connected to the ESP) and this should work.