I'm a software developer interested in creating an inexpensive device
that measures how fast I'm pedaling on my stationary recumbant bike and
that communicates that information to my computer via USB or RS-232.
Probably something along the lines of putting a magnet on the pedal and
a sensor on the body of the bike. Ideally, it should be powered by the
USB or RS-232 port itself.

I can take care of the software part, but I know very little about
electronics (just enough to do some basic soldering and some digital
circuits).

Can anyone recommend any existing [inexpensive] packaged solutions or
describe how I can build an electromagnetic proximity sensor
inexpensively?

Thanks,
Mark

On 2005-12-10, wrote:
I'm a software developer interested in creating an inexpensive device
that measures how fast I'm pedaling on my stationary recumbant bike and
that communicates that information to my computer via USB or RS-232.
Probably something along the lines of putting a magnet on the pedal and
a sensor on the body of the bike. Ideally, it should be powered by the
USB or RS-232 port itself.

I can take care of the software part, but I know very little about
electronics (just enough to do some basic soldering and some digital
circuits).

wire your sensor to the ring-indicte pin of your serial port and use
interrupts (or events from the OS-provided driver etc) to count the pulses.


--

Bye.
Jasen