In a previous post I created a simple timed shutter release from an Arduino, and used this to create a couple of time lapse videos. The drawback of this was that changing timing was a little tough - you had to update the source code and reflash the program to the Arduino.
Since I had a Raspberry Pi sitting around with similarly simple programmable GPIO pins I created a simple web frontend. Again hooking up the shutter release involved a pretty simple circuit based around a NPN transistor - I selected a random GPIO pin (pin 12):
I wrote this during winter and tried to capture a bit of snowmelt: