What is the battery voltage. If 5V or higher: connect to Vin. If 3.3V, connect to 3V3

Hmm, runnin' out of options here.. I do know that a certificate is not needed (run https without it myself), as you can test with another website. You also can connect to another site, so your ESP and IDF must be ok (imho). One last suggestion: (assuming you run php on the webserver): what happens w...

In the example the certificate isn't set either, so that proves it's not necessary. Is the server returning anything? You may try to set .is_async = false; Or, to test the connection to your own server, try this https example: https://docs.espressif.com/projects/esp-idf/en/latest/api-reference/proto...

Is the ESP32 the sending part (or, the client)? In that case there's no need for a certifcate, because a certificate is only to be sure that the client is connected to the right server (and not a mitm). So, the certifcate is recommended but not needed for the https connection itself.

The problem is the 50MHz oscillator on the LAN8720 board: it changes IO0 between high and low, so 50% chance the ESP32 will boot. As Sautter explains: he disables the oscillator during booting. It's not only a problem with flashing, but every time the ESP starts up. You can interrupt the wiring betw...

I've 1 port set as output on the ESP32. On HIGH, there's 5V on the port .
It's working fine for several months now, but I'm wondering: what is the maximum voltage on a port set as output?
I can imagine that it should be 3.3 volts, but I can't find any (maximum) ratings.

There's of course tons of in-depth information on the internet, so let's keep it simple: I would say the default way of light-dimming is leading edge trimming . If we would e.g. dim at 50%, we cut-off the first half of the half-sine. In other words, we ignite the triac half way the (half)sine wave. ...

For dimming purposes, you'll need a non-zero cross triac driver like MOC3023. MOC3063 won't work.