CO2 laser interference with ESP32

I made my own, third version co2 tube laser. I had problems with interference in previous versions, but I somehow fixed them then.

I upgraded to a 50w tube now, and the old friend has returned. My setup is… well, quite basic, and if pictures are needed, I can send pictures.
But first, if it is possible, could someone tell me basic points to follow when wiring up the tube with power supply?

For a test, I bought some shielded wire, and put my esp32 across the room, but it still is resetting when cutting. So I guess it isnt interference from being close to the laser, but being conducted through wires instead. Could I try to use optoisolator for the laser pwm? I am quite busy right now, and it comes with laziness to the laser making, so I am taking the easiest way out and asking in forum instead of problem solving myself.


Make sure the ground on the laser power supply(LPS) is connected to the ground of the ESP32 and is a good solid connection. You can not have too many ground connections.

remember, the only thing connecting the LPS to the ESP32 is the ground and the laser control signal(L).

I made mine as well. And I don’t have issues with the ESP32.
Project is here : my Trotec retrofit
I do use “twisted pairs” for all 3.3V signals coming from the ESP32 to the machine. Each one has ground and signal. It’s probably not as good as real shielded cable, but it works !

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Compared to @dougl setup I do use the LPS 5V to power my ESP32.
So I share ground, 5V and L signals.

Longer isn’t necessarily better. Longer can mean you have a longer antenna to pick up that interference.

Do you know that the shield in shielded wire needs to be connected only at one end? You should connect it to ground only at the end with the ground, and not at the other end.

Do post pictures, and include a wiring diagram that includes the ground wires and how they are connected.

Hello! I sort of forgot about this post, and I am sorry.
I found out what was the issue, and it’s really stupid. I had forgotten, that I used just plain tap water when setting up/testing my laser cutter. Slowly it got more alive and alive, till at one moment my whole laser was one big living high voltage monster.
Changed the water with distilled one, and now it’s working like a charm. I can’t believe all the stuff I did to the laser when in reality it was just the frickin water. Damnit