Quote:
Originally Posted by alexander.foti
I would say thats the issue as well, although I would like somebody who is experienced with the code to let me know if it is.
Surely I can just use a freq divider on the VSS signal to keep it seperate from the mpguino? Im no good with IDE like the arduino, and OK with electronics (if following instructions  ) |
With 120,000 pulses per mile, and going 78 MPH, your MPGuino is seeing a pulse about every 385 microseconds. That's about the time needed for the MPGuino hardware to respond to the interrupt request caused by the VSS pulse; and for MPGuino to execute the ISR for it, and return to the main display routine. If you go faster than 78 MPH at this point, the MPGuino will receive a second pulse as it is trying to process the first pulse, and the MPGuino will simply ignore the second pulse. 385 microseconds corresponds to 2600 Hz, which appears to be the VSS sampling cutoff frequency for the MPGuino.
The addition of a vss debounce of 1 ms is going to trash that VSS pulse length.
You're on the correct path. Putting a divide-by-16 circuit will drop down the VSS pulse frequency to something that MPGuino will handle.