Serial Over IP using ESP32 - MG5075 serial port max current that can be drawn?

[kohanyirobert]

Hey! I have an ESP32-S3-Zero laying around and thought I would hook it up with my alarm, MG5075.

I saw the Serial Over IP connection method, which makes sense, my only concern (because I'm no expert) is that could the ESP32 draw too much current from the board to damage it?

I looked up the board's manual, on the MG5075 PCB Layout page it is said that Max. aux. current: 2.5A, and The sum of the current drawn from the BELL and AUX must be limited to 4A., soooo I think I'll be okay, because I believe the ESP-S3-Zero draws about 500mA? Haven't tested it, will do sometime.

I know it's my call at the end of the day, but is it generally safe to do something like this?

My other idea is to power the thing from battery directly through a buck converted (since it is located beside the MG panel).

[yozik04]

Max. aux. current: 2.5A at 12V I think... So it is around 30 watts. ESP32 drains 0.3A at 3.3V. Which is 1 watt... You need to protect ESP32 from over current on it's pins. So you probably need a level shifter as well.
If I'd do, I'd power it from the same serial port via DC-DC converter. But you need to make sure which pin is which. So you need at least a multimeter...

[kohanyirobert]

I'd power the ESP-S3-Zero over USB-C (at least that's my intention, since USB has over current protection? I guess, without any confidence other than I saw something like that here and there).

If I'd do, I'd power it from the same serial port via DC-DC converter. But you need to make sure which pin is which. So you need at least a multimeter...

You mean you'd use the Serial port on the board with its 4 pin. VCC and GND connected to a DC-DC converter (buck converter), this would power the ESP (in my version via USB-C), and I connect the Tx and Rx to the appropriate pins on the board.

I do have a multimeter, so that's not an issue, I can do basic soldering and what not, but know next to nothing on protecting a complex PCB (Magellan) from over drawing currents through its circuits :)

[yozik04]

Correct. If you won’t short circuit anything and won’t provide too high power to the ESP then it should be fine. Why DC-DC, I think they need common ground to communicate. So I am not sure if USB-C variant will work. But I am not an expert.