Arduino Uno Pins
The ultimate cheat sheet for the world’s most popular microcontroller. This pinout reference maps the ATmega328P GPIOs to their specific functions, including PWM channels, Analog inputs, and dedicated communication pins like I2C and SPI.
| Pin Type | Arduino Uno Pins | Function |
|---|---|---|
| Power | 5V, 3.3V, GND, Vin | Voltage Supply |
| Analog In | A0 – A5 | 10-bit ADC Inputs |
| PWM Out | 3, 5, 6, 9, 10, 11 | Analog-style output (8-bit) |
| I2C | A4 (SDA), A5 (SCL) | Serial Communication |
| SPI | 11(M), 12(M), 13(S) | High-speed Data |
Current Limits: Always remember that the maximum current per I/O pin is 40mA, and the total for all pins combined should not exceed 200mA to avoid damaging the chip.
PWM Pins: Pins marked with a tilde (~) support Pulse Width Modulation, allowing you to simulate analog output levels for dimming LEDs or controlling servos.