Using an old hard drive cable, I built a GPIO breakout cable then proceed to make an LED blink... a classic 'Hello World' of electronics. I followed this diagram for the connections.
image from Embedded Linux Wiki
Plug the wires and follow these steps:
- Boot the Raspberry Pi
- Login as root (embrace your dark side)
- Getting ready to output in GPIO4:
- $ echo "4" > /sys/class/gpio/export
$ echo "out" > /sys/class/gpio/gpio4/direction
- Turn GPIO4 on:
$ echo "1" > /sys/class/gpio/gpio4/value
- Turn GPIO4 off:
$ echo "0" > /sys/class/gpio/gpio4/value
I'm now using WiringPI c++ library. Here's a good reference to get started at Limina.Log. And a good pins reference table.