MicrocontrollersQUICK REFERENCE
Raspberry Pi Pico
GPIO functions and header positions for the original RP2040 Pico.
01Header map
- GPIO
- GP0–GP22 and GP26–GP28 are exposed. All support PWM; channels share slices.
- ADC
- GP26 = pin 31, GP27 = pin 32, GP28 = pin 34; ADC ground = pin 33.
- Power pins
- VBUS 40; VSYS 39; GND 38; 3V3_EN 37; 3V3(OUT) 36; ADC_VREF 35.
02Bus examples
- I2C0
- SDA GP4 (pin 6) / SCL GP5 (pin 7).
- SPI0
- RX/MISO GP16 (21), CS GP17 (22), SCK GP18 (24), TX/MOSI GP19 (25).
- UART0
- TX GP0 (pin 1) / RX GP1 (pin 2).
- Analog scale
- Hardware ADC is 12-bit; MicroPython read_u16() scales to 0–65535.
03Board basics
- Power
- VSYS accepts 1.8–5.5 V per board documentation; GPIO never accepts 5 V.
- LED
- Original Pico LED is GP25; Pico W uses a different LED connection. Use Pin("LED").
- Bootloader
- Hold BOOTSEL while connecting USB to load UF2 firmware.