ESP32 not working if using external supply

[Jeditemple2001]

THANK YOU SO MUCH!!!

I came on this thread for an unrelated project but your throw away comment has just solved the problem with my previous project. I had assumed the onboard voltage step down was broken on my batch but thankfully it’s just a silkscreen issue (exactly as you suggested).

[PeteKnight]

Good, glad it helped someone else.

Pete.

[sahil_khan]

I am using an ESP32 with a relay and a PIR sensor in my project. The setup works flawlessly when powered through my system using a micro USB cable. However, when I switch to an external 5V 2A adapter for powering the ESP32, the project does not function as expected.

I also tried connecting the adapter directly to the ESP32’s micro USB port, but it still doesn’t work as it does when connected to the system.

Troubleshooting Steps Taken:

• Verified all wiring connections.
• Confirmed that the adapter is rated at 5V 2A, which should be sufficient for the setup.

Components in Use:

• ESP32
• Relay module
• PIR sensor

Request for Assistance:
I need help identifying the cause of this issue. Could it be related to power delivery differences between the system and the adapter, insufficient current, noise in the adapter’s output, or any other factor? Any suggestions or troubleshooting steps would be greatly appreciated.

[Madhukesh]

@PeteKnight

That type of problem is usually caused by the external power supply not ramping-up quickly enough and the the CPU missing the RESET signal generated by the circuitry on the board at power-up. The solution is to add a 10uF capacitor between your EN (RST) and GND pins.

You can test this easily by applying the external power supply to the 5v and GND pins then pressing the RST/EN button. If the board boots as normal when the button is released then the capacitor solution will work.

You should consider this suggestion @sahil_khan

[sahil_khan]

Thank you for replying, but I tried it, and it didn’t work.

[Madhukesh]

There are lots of other aspects to be checked and also the dev module might be defective. Try another module to rule out this issue… As this is issue is not related to Blynk, you might not find the help you need.

[brunog]

since you have a relay module in your circuit, check for presence of a flyback diode across the inductive load terminals

[PeteKnight]

@sahil_khan

I also tried connecting the adapter directly to the ESP32’s micro USB port, but it still doesn’t work as it does when connected to the system.

Assuming that you’ve wired the USB connector correctly then it’s pointing towards your power adapter being the issue.

Use a multimeter to check the voltage that’s appearing on the board when you power it this way.
If you have a phone charger with a micro USB cable then try powering it that way and see what happens.

Pete.