[Kurt] was using a bike trainer to get in shape for warmer and dryer biking months. Unfortunately it’s pretty hard to train if you don’t have reliable data concerning how hard you’re working. There’s commercial solutions for trainer computers but he’d read some rough reviews about them and decided to build his own trainer computer. He’s done a great job of integrating a lot of different data collection sources. He picked up two replacement bike computer sensors to use on the back wheel for speed (the front wheel is stationary with this type of trainer) and on the crank for cadence. He also wears a heart rate monitor and sourced a SparkFun heart rate module to gather that data. Finally, an LM235 analog temperature sensor was combined with a spring clamp to detect the temperature of the trainer’s resistance module.
Data from the sensors is collected with a PIC16F73 microprocessor and fed to a computer over a serial connection. He’s got a screenshot of the realtime graphs that he’s using for feedback while on the bike. This is a useful and practical setup but when he get’s tired of exercising he’s just a few lines of code from converting this into a gaming controller.