Thread: VSS limit
View Single Post
Old 08-20-2014, 04:59 PM   #5 (permalink)
EcoModding Lurker
Join Date: Nov 2008
Location: London UK
Posts: 95
Thanks: 3
Thanked 7 Times in 4 Posts
Originally Posted by P-hack View Post
that is a lot of pulses, given the delay changes the top speed then that seems like the problem. A dedicated atmega chip might be able to keep up with it, but not one that is monitoring injectors and displaying data on an lcd and keeping running 64 bit tallies. I would divide by 24, that is every time the vss edge changes 24 times, toggle the output pin, set pulses to a sane 5000/mi. Lunch off the existing 5v supply and intercept the vss, no oscillator required if vss is interrupt driven. @ 8mhz you have about 3000 cpu cycles to sort each edge out @ 78mph.
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 )
  Reply With Quote