Thanks for all the replies everyone.
I am going to try to find a way to attach a magnet to the trainer cylinder. There is some clearance issues that I will have to address. I have heard of magnetic paint, that would be a godsend. McMaster sells it for 30 USD a quart, though. I just need a few drops!
Are you trying to make your existing bicycle computer work when the bike is on the trainer, or add something completely separate?
I am trying to make something separate. I want to make a few visualizations in Processing to show time remaining on particular training intervals and I am going to have the bike speed sent wirelessly to the screen. I am still in concept stage, so let me know if anyone has any suggestions.
For example, certain regimes call for 20 min warm up, 15 min hard push, 3 min rest, 15 hard push, etc...
You should have gotten proper rollers