Controlling relays etc. with a Raspberry Pi
Friend and sometime co-conspiritor of mine Peter of Greenlight Electronics (who's shop website I've done some work on) manufactures and sells these relay controllers for the Raspberry Pi. I've been playing with it and its super easy to use, with various powering options for the load. Basically it has 8 open collector drivers that can pull down a maximum of 500mA (4A total for board) which is more than enough for relays, LED's and small motors (e.g N or OO gauge model trains!).
I've been playing with the board, and it's simple to control with basic calls from the GPIO.RPi python library. Soon I'll have some examples posted here when I have time ro do something more impressive than flashing LEDs :)
They're available from the Greenlight Electronics website here
Version 1 published 20 May 2015, 1:25 p.m.