Blink and heartbeat
Toggle the LED on GPIO 2 and print a tick every second. The first thing to flash on any new board.
ESP32
3V3
GND
EN
23
VP
22
VN
TX
34
RX
35
21
32
GND
33
19
25
18
26
5
27
17
14
16
12
4
GND
0
13
2
D2
15
D3
D1
CMD
D0
5V
CLK
Wiring
| From | To board | Note |
|---|---|---|
| LED anode, through 220 Ω | GPIO 2 | Skip if your board has an onboard LED |
| LED cathode | GND |
Tested on this board
Not run on this board yet. Treat the wiring and code as a first draft.
Firmware, Arduino sketch for ESP32 Dev Module
const int LED = 2;
void setup() {
Serial.begin(115200);
pinMode(LED, OUTPUT);
}
void loop() {
digitalWrite(LED, HIGH);
delay(500);
digitalWrite(LED, LOW);
delay(500);
Serial.printf("tick %lu ms\n", millis());
}Parts
| Quantity | Part | Where to buy |
|---|---|---|
| 1× | ESP32 dev board | Buy at Amazon |
| 1× | LED and 220 Ω resistor, only if your board has no LED on GPIO 2 |
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Libraries
None beyond the ESP32 Arduino core.
Load it
- In the Arduino IDE, install the esp32 board package and pick the board named above the sketch.
- Paste the sketch, choose the board's port and upload. Hold BOOT if the upload stalls at Connecting.
- Close the IDE's serial monitor, then open the bench here to watch the output.