If you’ve just received your Seeed Studio XIAO ESP32S3 Sense, this step-by-step guide will walk you through setting up the Arduino IDE, installing the correct board support, and running your first LED blink test.

1. Install Arduino IDE

• Download Arduino IDE 2.x from the official Arduino website.
• Install and launch the IDE.

2. Install ESP32 Board Support

1. Open Arduino IDE → File → Preferences
2. In Additional Board Manager URLs, add the following link:

https://espressif.github.io/arduino-esp32/package_esp32_index.json

3. Click OK to save.
4. Go to Tools → Board → Board Manager.
5. Search for esp32, then install esp32 by Espressif Systems (latest version, currently 3.3.0).

⚠️ Important:
Do not use Arduino ESP32 Boards by Arduino. That package has incomplete support. Always use Espressif Systems (official).

3. Select the Correct Board

Navigate to:
Tools → Board → esp32 → ESP32S3 Dev Module

(Even though the XIAO ESP32S3 is not explicitly listed, selecting “ESP32S3 Dev Module” works perfectly.)

4. Select the Serial Port

Go to Tools → Port and choose your device, e.g.:

/dev/ttyACM0

If you don’t see it:

• Try a different USB cable (must be a data cable, not a charge-only cable).
• On Linux, you may need to add your user to the dialout group:

sudo usermod -a -G dialout $USER

Log out and log back in.

5. Test the LED (Blink Example)

Create a new sketch (.ino) and paste the following code:

#define LED_BUILTIN 21   // Onboard yellow LED on GPIO21

void setup() {
  pinMode(LED_BUILTIN, OUTPUT);
}

void loop() {
  digitalWrite(LED_BUILTIN, HIGH);  // turn LED on
  delay(500);
  digitalWrite(LED_BUILTIN, LOW);   // turn LED off
  delay(500);
}

• Click Upload (→).
• If the small yellow LED starts blinking, everything is working! 🎉

6. Troubleshooting

• LED doesn’t blink
  • The power LED (always on) cannot be controlled. The correct controllable LED is the small yellow LED on GPIO21.
• Compilation error: missing partition CSV
  • Ensure you selected ESP32S3 Dev Module.
• No /dev/ttyACM0 port found
  • Check your USB cable (use a proper data cable).
  • Add user to dialout group (Linux).

✅ Conclusion

At this point, your XIAO ESP32S3 Sense is successfully set up with Arduino IDE. You can now control the onboard LED and are ready to explore more advanced features such as WiFi and the camera module.