| Pin | Name | Function | Type |
|---|---|---|---|
| 1 | RST | Reset | Control |
| 2 | 3V | 3.3V Output | Power |
| 3 | AREF | Analog Reference | Analog |
| 4 | GND | Ground | Ground |
| 5 | A0 | Analog 0 / DAC | Analog |
| 6 | A1 | Analog 1 | Analog |
| 7 | A2 | Analog 2 | Analog |
| 8 | A3 | Analog 3 | Analog |
| 9 | A4 | Analog 4 / SDA | Analog/I2C |
| 10 | A5 | Analog 5 / SCL | Analog/I2C |
| 11 | SCK | SPI Clock | SPI |
| 12 | MOSI | SPI MOSI | SPI |
| 13 | MISO | SPI MISO | SPI |
| 14 | RX | UART Receive | UART |
| 15 | TX | UART Transmit | UART |
| 16 | D4 | Digital 4 | GPIO |
| Pin | Name | Function | Type |
|---|---|---|---|
| D0 | RX | UART Receive | UART |
| D1 | TX | UART Transmit | UART |
| D2-D13 | Digital | Digital I/O (PWM on 3,5,6,9,10,11) | GPIO |
| A0-A5 | Analog | Analog Input (10-bit ADC) | Analog |
| SDA | SDA | I2C Data | I2C |
| SCL | SCL | I2C Clock | I2C |
| 5V | 5V | 5V Power Rail | Power |
| 3.3V | 3V3 | 3.3V Power Rail | Power |
| VIN | VIN | External Power Input | Power |
| GND | GND | Ground | Ground |
| Pin | Name | Function | Type |
|---|---|---|---|
| 0 | GPIO0 | Digital / PWM / I2C SDA | GPIO |
| 1 | GPIO1 | Digital / PWM / LED | GPIO |
| 2 | GPIO2 | Digital / Analog / I2C SCL | GPIO |
| 3 | GPIO3 | Digital / Analog / USB+ | GPIO |
| 4 | GPIO4 | Digital / Analog / USB- | GPIO |
| — | BAT+ | Battery / USB 5V | Power |
| — | GND | Ground | Ground |
| — | RST | Reset | Control |