Progress Update 2006-10-27
Well it's been a while since I updated this blog, again.
Since the last update I've been experimenting with generating and handling interrupts generated by Timers and GPIO pins.
With a simple circuit using a reed switch and a magnet, a pulse can be generated which can then trigger an interrupt on a GPIO pin. By counting the number of pulses and measuring the time between pulses, we can calculate a number of different metrics. If the magnet is attached to the wheel and we know the diameter of the wheel we can calculate speed and distance, and if the magnet is attached to the crankset we can calculate cadence.