Darlington Driver Arduino to Control Remote


I have a remote controller to control 3 switches for my lighting in my house. It is a very handy device.

However I would like it to be computer controlled so i set off hacking it. As it turns out when a button is pressed 3 leads are connected. A ground pin a on or off pin and a pin for the lamp (1, 2 and 3). So I thought to just use 3 transistors to switch the buttons on or off. One to connect 1,2 or 3 to ground then one to connect the previous bunch to on and one for off. I tried the setup and it worked for one lamp. I then thought if there wasn’t a way do decrease the amount of transistors and wiring. Then I came across a darlington array IC, the uln2804ag. But i just cant get it to work. So can some body tell me how to wire this up with the arduino?

Many years ago I made a simple setup so I could change my tv channels from work. The link below shows how I used a transistor to do the button push on an IR remote control.