[LAU] A crazy idea

[James Morris]

On Thu, March 4, 2010 09:48, Jonathan Gazeley wrote:

> 1. A sensor that can measure my cadence. A simple magnet switch that
> triggers once a revolution won't be enough to measure the cadence with
> sufficient resolution, since my cadence is usually between 50 and 80
> rpm. I would probably need to mount multiple magnets spaced equally
> around the chainwheel and have a single sensor on the frame. Then I have
> to get it to supply this information to my control program.

Cycle computers which measure cadence work with a single magnet on the
crank and can measure cadence in that range and above. I think the fastest
RPM I ever got was (only a vague memory) around 120 (maybe?) when I was
being silly trying to see how fast I could pedal.


> I have absolutely no idea why I would want such a device - just for the
> fun of building it, I guess. I would like it to work in realtime (rather
> than later generating the soundtrack from recorded cadence data). The
> thought of sitting at the traffic lights with my earphones in and then
> hearing the mighty roar of a V8 as I pull away would be really
> satisfying...

Would it not be better to have a pair of mighty speakers in the shape of
twin exhaust pipes sticking out the back so every one else can hear the
roar :-D