ESP32DEV C3 Serial Port Not Working Correctly

Development Tools IDE 1.x
1

With this very simple code, the LED is blinking correctly as expected, but there are no outputs from the serial ports. I've tried setting the baud rate to 9600 and 115200 but didn't work. I've tried reset method and reinstalling Arduino but still have no outputs.

void setup() {
  Serial.begin(115200);
  pinMode(1,OUTPUT);
}

void loop() {
  digitalWrite(1,HIGH);
  while(!Serial);
  delay(100);
  Serial.println("hello");
  digitalWrite(1,LOW);
  delay(100);
}
2

Did you activate the "USB CDC on boot option"?

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image744×197 31.4 KB

2 Likes
3

Are you using the following ESP32 C3 Super Mini board?

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image204×247 17.1 KB

4

Which IDE are you using? IDE 1.x?

5

Hi @kp4good ,

the led connected to pin 1 quite likely interferes with Serial on UART0

Screenshot_2025-01-13-10-26-12-26_40deb401b9ffe8e1df2f1cc5ba480b12
Screenshot_2025-01-13-10-26-12-26_40deb401b9ffe8e1df2f1cc5ba480b121079×1237 163 KB

Source: https://randomnerdtutorials.com/esp32-uart-communication-serial-arduino/#esp32-uart-peripherals

What happens if you move the led to a different pin?

Good luck!
ec2021

6

Thank you for your advice! Seems like there are conflicts between the pins. After switching to a different project and unplugging the pins the Serial seems to be working fine.

7

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