The GPIO Connector

The diagram below show the pins on the GPIO connector for a Raspberry Pi Version 1 (which is what existed when this tutorial was released) Version 2 has pin 27 replacing pin 21 but it otherwise the same

As well as supplying power (GND, 3.3V and 5V) all the GPIO pins can be used as either digital inputs or outputs. The pins labelled SCL and SDA can be used for I2C. The pins labelled MOSI, MISO and SCKL can be used to connect to high speed SPI devices.

All the pins have 3.3V logic levels and are not 5V-safe so the output levels are 0-3.3V and the inputs should not be higher than 3.3V. If you want to connect a 5V output to a Pi input, use a level shifter

A popular way to actually make the connections to the Raspberry Pi is to use a Pi Cobbler.

Make extra extra double-check sure that the PIN 1 indicator is in the corner of the Pi. If you have a gray cable its probably a red stripe, for black cables, a white stripe. That pin must not be next to the TV connector. Turn around or twist the cable until it is right

This uses a ribbon cable to connect the GPIO connector to solderless breadboard, where you can add your own components.

Last updated on 2015-05-04 at 04.27.11 PM Published on 2012-12-14 at 09.28.57 AM