<![CDATA[Serial not working with M5Unified on AtomS3]]>Hi,

I am using M5Unified on my AtomS3 but can't get Serial.println("hello") to show up on the host. I configured the baud rate correctly and things worked on a previous project without M5Unified on an AtomLite. I guess I am missing something obvious here.

Any help welcomed.

Marc

]]>https://community.m5stack.com/topic/5858/serial-not-working-with-m5unified-on-atoms3RSS for NodeWed, 29 Apr 2026 06:54:35 GMTFri, 01 Dec 2023 18:40:34 GMT60<![CDATA[Reply to Serial not working with M5Unified on AtomS3 on Sat, 02 Dec 2023 10:25:13 GMT]]>Thanks @teastain for the hint with USB CDC on Boot!

I forgot to mention that I am on PlatformIO but the snippet shown below added to the platform.ini file helped me to solve the problem. Previously I didn't had to specify any build_flags to see the Serial output, so maybe this is a change introduced by PlatformIO.

monitor_speed = 115200
build_flags = 
	-D ARDUINO_USB_MODE=1
	-D ARDUINO_USB_CDC_ON_BOOT=1

Best
Marc

]]>https://community.m5stack.com/post/22940https://community.m5stack.com/post/22940Sat, 02 Dec 2023 10:25:13 GMT<![CDATA[Reply to Serial not working with M5Unified on AtomS3 on Fri, 01 Dec 2023 22:15:54 GMT]]>@frameworklabs This worked for me with my cute AtomS3!

#include <M5Unified.h>

void setup() {
  M5.begin();
  Serial.begin(115200);
  M5.Lcd.fillScreen(BLACK);
  delay(100);
}

void loop() {
  Serial.println("loop");
  M5.update();
  M5.Lcd.setTextColor(RED);
  M5.Lcd.setTextSize(2);
  M5.Lcd.setCursor(25, 15);
  M5.Lcd.print("RED");
  M5.Lcd.setTextColor(BLUE);
  M5.Lcd.setTextSize(2);
  M5.Lcd.setCursor(18, 50);
  M5.Lcd.print("BLUE");
  M5.Lcd.setTextColor(GREEN);
  M5.Lcd.setTextSize(2);
  M5.Lcd.setCursor(15, 90);
  M5.Lcd.print("GREEN");
  delay(100);
}

But with Tools setting: USB CDC on Boot 'enabled'
-Terry

]]>https://community.m5stack.com/post/22939https://community.m5stack.com/post/22939Fri, 01 Dec 2023 22:15:54 GMT