Quick wheel decoder question....

DaveW · Post by **DaveW** » Wed Jul 05, 2006 2:38 am

MS1, V3 board, MSnSE 29q2

Can anyone confirm if the wheel decoder pin at the CPU actually triggers on the leading or trailiing edge of the incoming pulses ?

See the LS1 thread for more details but essentially I have a 5V conditioned square wave signal fed from the crank sensor that is suitable for connecting direct to the CPU input pin but it needs to trigger on the trailing edge of the pulse. If the CPU triggers on the leading edge I'll have to invert the signal.

The trailing edge is a consistent, evenly spaced pulse train, the leading edge varies in position as the teeth of a mix of widths so I can't really trigger on the leading edge.

Post by **jsmcortina** » Wed Jul 05, 2006 4:12 am

The ~IRQ pin triggers on the falling edge. The second trigger is software configurable.

James

DaveW · Post by **DaveW** » Wed Jul 05, 2006 8:21 am

Should have just asked you in the first place James

Thanks, that makes life easier !