My dad was initially going to program a basic few step and loop program by building a computer chip. His ability to build a program using circuits was enough to amaze me, you don't get taught that in the Bachelor of IT!

However after talking to me about what I wanted, he realised I wanted something a bit more complex. I.e. turn a bit on one antennae, the other one another bit, at the same time sometimes, different directions and different distances in one movement and different speeds.

So online (maybe eBay again) he found a programmable computer chip, where you simple created a program and it was uploaded to the chip.

The movement pattern is up to you and how obvious/subtle you want the movement to be. Suprisingly once you start walking around, movement you thought once was much to obvious now appears quite a bit more subtle. You also need to consider how many movements are in each loop.

Additionally, it is important to ensure through how far you make the antennae move one way or the other, that in each loop the movement one way is cancelled out by the other way, so that the antennae remain centred.

The board/chip we bought came with a few buttons, so dad programmed it to be able to move each antennae when each button was pressed, so if after a few hours the antennae are not centered, they can be manually alligned.