ESP32 Forum

Hey everyone
I've built a project with esp-wroom-32 and after a few days of running, the esp32 turned off and when I connected it to my computer it started smoking.
I'm not sure what made it happen, it's the second time it has happened to me with this project.
I made a schematic of my project so you guys can see it and hopefully find what's wrong with it.
The servo is connected to a relay so it's not on all the time (because it's making noise), it's turned on only when I want to move the servo.
I trigger the servo to move using WIFI or using the push button.
I suspect that the relay made the esp32 burn because it drew too much current from the 3v3 pin, if it's the case, I would be happy if someone can suggest me another way to power up the relay (I tried using an external 5v but it won't work because the signal is connected to 3v GPIO)

Yes you are propably right the relay takes too much current for the DO
Why do you need this relay anyway
If you do need it why not use a simple transistor to run the relay. This uses 12V but 5V relay will do what you want

There are a couple of possible reasons i can think of:

- Does your relay board has an optocoupler? its important to keep the output eletrically isolated from the relay, it draws way too much current for the output, and its a good idea having an diode to protect against switching surges (reference https://resources.pcb.cadence.com/blog/ ... protection)

- Can you check if the AMS1117 (voltage regulator) is working? maybe the relay draw too much current for it, usually when it burns you can see a small spot on top of the component. Servos and relays are inductive and draw a lot of current when turning on, this could have killed the AMS1117. I always like to use an eletrolityc capacitor in parallel with the servo. If this is the case, the AMS1117 is very cheap and you can just replace it.

An altenate solution to the relay is to use an transistor (i like to use logic level mosfets). this will save power compared to the relay, be quieter and last way longer. (add the optocoupler to drive the mosfet). This video can give a good reference: https://www.youtube.com/watch?v=vudSUDFWoQE

Try checking if when you kill the PWM output the servo goes to idle, if it does, you wont need any additional circuit, just use detach (if you are using the arduino library) or disable the PWM output.

Tip about noise: i had noise issues in the past while working with 3DPrinters and a long cable, if i remember correctly i fixed it with an 10nf or 100nf ceramic capacitor very close to the servo, from the PWM signal to ground (or vcc, its been too long)