Speedo signal question (non-perf)

Jon Davis jfdavis@epix.net
Thu, 2 May 2002 19:11:07 -0500


Edgar Sagastume wrote:

> I4m building a home made Trip-computer for my se-r and need some help for
my

I did the same thing about 2 years ago using an Atmel AVR microcontroller. I
still use it in my car today for mpg calcs etc. If you want some
circuits/software etc, email me privately I'll see if I can dig up my notes.
If you are just doing it for fun... the wheel sensor gives 2 short pulses
per tire revolution, maybe 10% duty cycle - the magnetic switch is pretty
dirty and needs debounced. I used a Schmitt trigger and a RC circuit to make
it work. That is also an input to the ECU so be careful of your input
impedance.

Jon Davis