Loading source-backed pinouts…
Linux SBC · SBC
Raspberry Pi 4 Model B
A widely deployed Linux SBC with the same 40-pin expansion header used across modern Raspberry Pi boards.
Processor
Broadcom BCM2711
Logic
3.3 V GPIO
Power
5 V USB-C, 5 V header rail
Format
Credit-card SBC
Check before wiring
- Header power pins are not current-limited like GPIO pins.
- Check UART overlays before assuming serial availability on pins 8 and 10.
Interfaces
GPIOI2CSPIUARTPWMCSIUSBEthernet
Source-backed connector
Interactive pin map
Pin map
Raspberry Pi 4 Model B
Component view / J8 40-pin GPIO header
Component placement is illustrated; small components and markings may vary with board revision. Decorative traces do not represent electrical connections.
All 40 pins (table)
40 / 40 pins
| Pin | Signal | Function / note | Actions |
|---|---|---|---|
| 1 | 3V3Power | Power | |
| 2 | 5VPower | Power | |
| 3 | GPIO2I2C | SDA1 | |
| 4 | 5VPower | Power | |
| 5 | GPIO3I2C | SCL1 | |
| 6 | GNDGround | Ground | |
| 7 | GPIO4GPIO | GPCLK0 | |
| 8 | GPIO14UART | TXD0 | |
| 9 | GNDGround | Ground | |
| 10 | GPIO15UART | RXD0 | |
| 11 | GPIO17GPIO | GPIO | |
| 12 | GPIO18PWM | PWM0 | |
| 13 | GPIO27GPIO | GPIO | |
| 14 | GNDGround | Ground | |
| 15 | GPIO22GPIO | GPIO | |
| 16 | GPIO23GPIO | GPIO | |
| 17 | 3V3Power | Power | |
| 18 | GPIO24GPIO | GPIO | |
| 19 | GPIO10SPI | SPI0 MOSI | |
| 20 | GNDGround | Ground | |
| 21 | GPIO9SPI | SPI0 MISO | |
| 22 | GPIO25GPIO | GPIO | |
| 23 | GPIO11SPI | SPI0 SCLK | |
| 24 | GPIO8SPI | SPI0 CE0 | |
| 25 | GNDGround | Ground | |
| 26 | GPIO7SPI | SPI0 CE1 | |
| 27 | GPIO0Reserved | ID_SD | |
| 28 | GPIO1Reserved | ID_SC | |
| 29 | GPIO5GPIO | GPIO | |
| 30 | GNDGround | Ground | |
| 31 | GPIO6GPIO | GPIO | |
| 32 | GPIO12PWM | PWM0 | |
| 33 | GPIO13PWM | PWM1 | |
| 34 | GNDGround | Ground | |
| 35 | GPIO19Alt | PCM FS | |
| 36 | GPIO16GPIO | GPIO | |
| 37 | GPIO26GPIO | GPIO | |
| 38 | GPIO20Alt | PCM DIN | |
| 39 | GNDGround | Ground | |
| 40 | GPIO21Alt | PCM DOUT |
- Physical pins 1 and 17 are 3.3 V; pins 2 and 4 are 5 V.
- GPIO0 and GPIO1 on pins 27 and 28 are reserved for HAT ID EEPROM use on most setups.
- GPIO pins are 3.3 V logic and are not 5 V tolerant.
Why it matters
- Useful baseline board for Pi HAT and jumper-wire projects.
- Lots of community examples map to this exact header.
- Gigabit Ethernet and multiple USB ports make it practical as a lab controller.
Keep exploring