Step 5: First Program – Blink Onboard LED

According to your CoreLab board, there is a built-in LED connected to GPIO 15.

Easiest Way:

1. Go to File → Examples → 01.Basics → Blink.

2. In the code, change LED_BUILTIN to 15 in both pinMode and digitalWrite lines.

3. Click Upload.

Manual Code (Recommended – Copy and Paste This):

// the setup function runs once when you press reset or power the board

void setup() {

  // initialize digital pin 15 as an output.

  pinMode(15, OUTPUT);

}

// the loop function runs over and over again forever

void loop() {

  digitalWrite(15, HIGH);   // turn the LED on (HIGH is the voltage level)

  delay(1000);              // wait for a second

  digitalWrite(15, LOW);    // turn the LED off by making the voltage LOW

  delay(1000);              // wait for a second

}

How to Upload:

1. Click the Verify button (✓) to check the code.

2. Click the Upload button (→).

3. If upload fails, hold the BOOT button on the board while clicking Upload, then release it.

After successful upload, you should see the onboard LED (connected to pin 15) blinking on and off every second.

Step 6: Troubleshooting

• No port appears → Install CH340 driver (Step 3.1) and reconnect.

• Upload error → Hold BOOT button during upload.

• LED not blinking → Confirm you changed the pin to 15. Try a longer delay (e.g., 2000) to see it clearly.

• Board disconnects during upload → Use a better USB-C data cable.

 Great! The board is now ready for all ESP32 CoreLab projects. 🚀