| Pin | Name | Function |
|---|---|---|
| 1 | GP0 | UART0 TX, I2C0 SDA, SPI0 RX |
| 2 | GP1 | UART0 RX, I2C0 SCL, SPI0 CSn |
| 3 | GND | Ground |
| 4 | GP2 | SPI0 SCK, I2C1 SDA |
| 5 | GP3 | SPI0 TX, I2C1 SCL |
| 6 | GP4 | UART1 TX, I2C0 SDA, SPI0 RX |
| 7 | GP5 | UART1 RX, I2C0 SCL, SPI0 CSn |
| 8 | GND | Ground |
| 9 | GP6 | I2C1 SDA, SPI0 SCK |
| 10 | GP7 | I2C1 SCL, SPI0 TX |
| 11 | GP8 | UART1 TX, I2C0 SDA, SPI1 RX |
| 12 | GP9 | UART1 RX, I2C0 SCL, SPI1 CSn |
| 13 | GND | Ground |
| 14 | GP10 | I2C1 SDA, SPI1 SCK |
| 15 | GP11 | I2C1 SCL, SPI1 TX |
| 16 | GP12 | UART0 TX, I2C0 SDA, SPI1 RX |
| 17 | GP13 | UART0 RX, I2C0 SCL, SPI1 CSn |
| 18 | GND | Ground |
| 19 | GP14 | I2C1 SDA, SPI1 SCK |
| 20 | GP15 | I2C1 SCL, SPI1 TX |
| 21 | GP16 | UART0 TX, I2C0 SDA, SPI0 RX |
| 22 | GP17 | UART0 RX, I2C0 SCL, SPI0 CSn |
| 23 | GND | Ground |
| 24 | GP18 | SPI0 SCK, I2C1 SDA |
| 25 | GP19 | SPI0 TX, I2C1 SCL |
| 26 | GP20 | I2C0 SDA |
| 27 | GP21 | I2C0 SCL |
| 28 | GND | Ground |
| 29 | GP22 | General purpose I/O |
| 30 | RUN | Reset (active low) |
| 31 | GP26_A0 | ADC0, I2C1 SDA |
| 32 | GP27_A1 | ADC1, I2C1 SCL |
| 33 | AGND | Analog ground |
| 34 | GP28_A2 | ADC2 |
| 35 | ADC_VREF | ADC reference voltage |
| 36 | 3V3(OUT) | 3.3V power output |
| 37 | 3V3_EN | 3.3V regulator enable |
| 38 | GND | Ground |
| 39 | VSYS | Main system power input (1.8V-5.5V) |
| 40 | VBUS | USB 5V input |
Summary
Small, cheap microcontroller board built around the RP2040 chip. No built-in Wi-Fi/Bluetooth (that's the separate Pico W) — this is the base version, good for simple sensor/control projects where you don't need wireless. Full 40-pin GPIO header shown; exact I2C/SPI/UART alternate-function mapping per pin should be checked against the official datasheet before critical use.
- MCU: RP2040, dual-core Cortex-M0+, up to 133MHz
- Flash: 2MB
- GPIO: 26 multi-function pins, 3 ADC inputs
- Wireless: None (see Pico W for Wi-Fi/Bluetooth)
- Supply voltage: 1.8V - 5.5V via VSYS, 3.3V logic