Raspberry Pi Pinout

Legend

  • GPIO (General Purpose IO)
  • SPI (Serial Peripheral Interface)
  • I2C (Inter-integrated Circuit)
  • UART (Universal Asyncronous Receiver/Transmitter)
  • Ground
  • 5v (Power)
  • 3v (Power)

3v3 Power

  • Physical pin 1

The 3v3 supply pin on the early Raspberry Pi had a maximum available current of about 50 mA. Enough to power a couple of LEDs or a microprocessor, but not much more.

All Raspberry Pi since the Model B+ can provide quite a bit more, up to 500mA to remain on the safe side, thanks to a switching regulator.

Still, you should generally use the 5v supply, coupled with a 3v3 regulator for 3.3v projects.