Pins
The following tables give the mapping of the Raspberry Pi GPIO Pins to the GPIO connector in relation to the pin numbers and the physical location on the connector. This is a representation of the GPIO connector as viewed looking at the board from above, with the USB power at the top and the GPIO to the top-right of the board.
If using the connector pin numbering, then note that Pin 1 on the connector is the 3.3v supply. Pin 2 is the 5V supply, and pin 26 is marked SPI CE1 below.
P1: The Main GPIO connector:
| wiringPi Pin | BCM GPIO | Name | Header | Name | BCM GPIO | wiringPi Pin |
|---|---|---|---|---|---|---|
| – | – | 3.3v | 1 | 2 | 5v | – | – |
| 8 | R1:0/R2:2 | SDA0 | 3 | 4 | DNC | – | – |
| 9 | R1:1/R2:3 | SCL0 | 5 | 6 | 0v | – | – |
| 7 | 4 | GPIO7 | 7 | 8 | TxD | 14 | 15 |
| – | – | DNC | 9 | 10 | RxD | 15 | 16 |
| 0 | 17 | GPIO0 | 11 | 12 | GPIO1 | 18 | 1 |
| 2 | R1:21/R2:27 | GPIO2 | 13 | 14 | DNC | – | – |
| 3 | 22 | GPIO3 | 15 | 16 | GPIO4 | 23 | 4 |
| – | – | DNC | 17 | 18 | GPIO5 | 24 | 5 |
| 12 | 10 | MOSI | 19 | 20 | DNC | – | – |
| 13 | 9 | MISO | 21 | 22 | GPIO6 | 25 | 6 |
| 14 | 11 | SCLK | 23 | 24 | CE0 | 8 | 10 |
| – | – | DNC | 25 | 26 | CE1 | 7 | 11 |
| wiringPi Pin | BCM GPIO | Name | Header | Name | BCM GPIO | wiringPi Pin |
- Board Revisions: Please note the differences between board revisions 1 and 2 (R1 and R2 above)
P5: The auxilliary GPIO connector present on Rev. 2 boards only:
| wiringPi Pin | BCM GPIO | Name | Header | Name | BCM GPIO | wiringPi Pin |
|---|---|---|---|---|---|---|
| – | – | 5v | 1 | 2 | 3.3v | – | – |
| 17 | 28 | GPIO8 | 3 | 4 | GPIO9 | 29 | 18 |
| 19 | 30 | GPIO10 | 5 | 6 | GPIO11 | 31 | 20 |
| – | – | 0v | 7 | 8 | 0v | – | – |
| wiringPi Pin | BCM GPIO | Name | Header | Name | BCM GPIO | wiringPi Pin |
- DNC -> Do Not Connect. These pins are reserved for future use and should not be connected to at this point in time.
Each side has three columns. The outermost column, headed wiringPi Pin refers to the pin number in the wiring Pi code. The middle one, headed BCM GPIO refers to the pin number of the BCM2835 chip, an this is the pin number used when addressing the GPIO using the/sys/class/gpio interface. The innermost column, Name is the name of the function of the pin.
The central column contains the pin numbers on the header on the board. Pin 1 is the 3.3v power supply on the P1 connector (Rev. 1 and Rev. 2 boards), and Pin 1 is the 5v power supply on the P5 connector on Rev. 2 boards only.
