ESP32 DevKit V1 pin guide
Safe pins, input-only pins, strapping pins and ADC2 with Wi-Fi.
| Group | Pins | Notes |
|---|---|---|
| Safe general purpose | 4, 13, 16–19, 21–23, 25–27, 32, 33 | Best choices for LEDs, buttons and modules |
| Input-only | 34, 35, 36 (VP), 39 (VN) | No output, no internal pull-ups |
| Strapping | 0, 2, 5, 12, 15 | Affect boot mode — avoid pull resistors at start-up |
| Flash (not on headers) | 6–11 | Never use |
| UART0 | 1 (TX), 3 (RX) | USB serial — avoid |
| I²C default | 21 (SDA), 22 (SCL) | |
| DAC | 25, 26 | 8-bit true analog output |