Raspberry Pi Pinout
GPIO 3 (I2C Clock)
| Alt0 | Alt1 | Alt2 | Alt3 | Alt4 | Alt5 |
|---|---|---|---|---|---|
| I2C1 SCL | SMI SA2 | DPI HSYNC | AVEOUT HSYNC | AVEIN HSYNC |
- Physical/Board pin 5
- GPIO/BCM pin 3
- Wiring Pi pin 9
- GPIO/BCM pin 1 on Rev 1 ( very early ) Pi
SCL (I2C1 Clock) is one of the i2c pins on the Pi, learn more about i2c.
SCL includes a fixed, 1.8 kΩ pull-up to 3.3v, which means this pin is not suitable for use as a general purpose IO where no pull-up resistor is desired.
