ESP32 Forum

Hi all,
I'm using and ESP32-WROOM dev board and it works fine when powered through USB.
But I'm having problems powering it from an external power source. When giving power by the 5V pin, the board works only if the applied voltage is higher than 9V otherwise it reboots continuously.
When powering from the 3.3V pin the board has the same behaviour. I tried to apply 3.4V but it doesn't solve the problem.
I tried also using capacitors from 200uF to 1000uF but it still reboot.
I'm using a bench power supply.
What should I try?

I'd say it's likely a problem in your hardware. Devboards like these pass the 5V USB via the same path as they do with external 5V, so needing to use 9V is very unlikely assuming everything in your hardware is correct. You didn't happen to set a current limit on your power supply that is too low, by the way?

I tried to rise the current limit up to the maximum value but the problem persists.
I did some more testing and found it reboots due to wifi. When disabling wifi the board works perfectly.
Using a delay of 50ms before to execute the code solved the problem. Maybe the capacitor needs this time to load.

Ah, that's likely it. Instead of waiting 500mS, you could also add an 10u capacitor (or something roughly around that range) between EN and GND, that'll delay the reset a bit.