It's not specifically geared towards your specific flavor of the ESP32, but it would not matter much at all.
https://learnesp32.com/videos/course-in ... troduction

Can you post your code?

However, the actual manual switch on my fireplace runs with very little voltage. About 0.2v.

Something does not sound correct there. Maybe its AC and your reading with a DC meter ?

Best bet is to use a relay.

You need to use a RJ45 that supports POE. I.E. it brings out the POE pins.
something like ARJM11D7-114-AB-EW2
For the POE power supply I have use the AG9903-MTB.

He brings up a good idea. I dont know if it could be implemented in menuconfig. It would be a nice feature to enable/disable those bootstrap pins.

As far as I know, printf will not work in Arduino frameworks. Rather it should be Serial.print()

FYI, printf works just fine in Arduino.

I got it working. Thank you guys for the help!

Seems pretty trivial to me: the functions take int16_t types

FWIW, in the example this function " dsps_tone_gen_f32(x1, N, 1.0, 0.16, 0); "
fills x1 with float values from -1.0 to 1.0. Why do you say it takes int16_t types ?

I apologize if that is how my statement came off. It's intention was just to explain I am under the gun on something I know very little about, and could use some help in a big way is all. You'r expiation was very helpful. Embarrassing obvious now that it was pointed out. If I take the fft example as...

I have thank you, but its not clear to me what is the min/max values my data needs to be to pass to the functions.