ESP32-S2 reset loop on startup, sometimes it boots
Posted: Wed Nov 05, 2025 9:06 am
Hello, I'm having a problem with esp32-s2 (specifically the S2-MINI-N4 module)
I have this module on a custom board. when I reset it, it enters a boot reset loop, dumping this into serial:
Sometimes, after seemingly random amount of reset cycles, it boots and runs my code.
The code is just a LED blink with serial:
My platformio.ini file is this:
Do you know what could be causing this? the same setup worked correctly on a previous revision of my board, so I suspect it might be a hardware problem.
I checked power with oscilloscope, the 3V3 is solid.
Basically all pins are connected to something. Are there any specific pins I should check?
I have this module on a custom board. when I reset it, it enters a boot reset loop, dumping this into serial:
Code: Select all
rst:0x3 (RTC_SW_SYS_RST),boot:0x1b (SPI_FAST_FLASH_BOOT)
Saved PC:0x400512fe
SPIWP:0xee
mode:DIO, clock div:1
load:0x3ffe6100,len:0x524
load:0x4004c000,len:0xa70
load:0x40050000,len:0x2958
entry 0x4004c18c
ESP-ROM:esp32s2-rc4-20191025
Build:Oct 25 2019The code is just a LED blink with serial:
Code: Select all
#include <Arduino.h>
const int LED_PIN = 2; // On-board LED is usually GPIO 2
void setup() {
Serial.begin(115200); // Start Serial Monitor
delay(1000); // Give time for Serial to open
Serial.println("ESP32 Blink Test Starting...");
pinMode(LED_PIN, OUTPUT);
}
void loop() {
Serial.println("LED ON");
digitalWrite(LED_PIN, HIGH);
delay(1000); // Wait 1 second
Serial.println("LED OFF");
digitalWrite(LED_PIN, LOW);
delay(1000); // Wait 1 second
}Code: Select all
[env:esp32-s2-saola-1]
platform = espressif32
board = esp32-s2-saola-1
framework = arduino
monitor_speed = 115200
monitor_filters = esp32_exception_decoderI checked power with oscilloscope, the 3V3 is solid.
Basically all pins are connected to something. Are there any specific pins I should check?