ESP32 keeps rebooting with rst:0x1 (POWERON_RESET)

Hi everyone,

I'm having an issue where my ESP32 constantly reboots with rst:0x1 (POWERON_RESET), even when running a simple loop() that just prints millis() and free heap every 2 seconds. There are no exceptions or panic messages — just a clean reboot, as if the board briefly loses power.

I left the board running during the weekend and it was working fine on Friday. Now, on Monday, it keeps rebooting. I simplified the code to rule out software issues, but the problem continues.

What I’ve tried:

Powered the ESP32 through multiple USB cables and ports

Powered it using a 12V power supply

Replaced the AMS1117-3.3 voltage regulator

Tried disabling brownout detection in code with WRITE_PERI_REG(RTC_CNTL_BROWN_OUT_REG, 0);

Symptoms:

Reboots occur after around 50 to 80 seconds

It always shows:

rst:0x1 (POWERON_RESET), boot:0x13 (SPI_FAST_FLASH_BOOT)

esp_reset_reason() returns 1 (POWERON_RESET)

No crashes or Guru Meditations

I’ll attach the schematic. Any ideas or suggestions would be greatly appreciated.

Thanks.

Sorry if this is in the wrong category.

Please post a link to the relay datasheet and the 12 to 5 volt converter.

Relay: https://components.omron.com/eu-en/sites/components.omron.com.eu/files/datasheet_pdf/K048-E1.pdf

12v to 5v: https://www.ti.com/lit/ds/symlink/lm2596.pdf

The chip restarts even when I power it only with 5V from USB going into the 5V-to-3.3V converter. However, the same 5V line before the converter is also connected to the relay circuitry