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Old 12-20-2010, 09:09 PM   #9 (permalink)
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From what little I have read I don't think the current form of the MPGuino can give good accuracy with dual injector TBI systems. This thread has some discussion on TBI injector systems.

I expect it will be necessary to monitor both injectors which is beyond the current capability but may not be that difficult to add. I have a couple thoughts on how to solve this with some relatively simple logic circuitry.

I think the best approach would be change the injector input conditioning circuitry so that only one interrupt is needed to monitor an injector. This would allow the two interrupts to monitor separate injectors rather then both being used for one injector. As I understand the problem an interrupt can either be set to trigger on rising edge or falling edge but not both and efforts to toggle that in the service routine were not successful at working round this.

I think that by moving the injector state input to another digital input then have a pulse generator circuit that makes a short interrupt pulse for each rising edge and falling edge of the injector pulse. The interrupt service routine just has to read the injectors state input to tell if the interrupt was for the rising or falling edge of the injector pulse.

I could come up with the input circuit for this if the code gods are willing to churn out the software changes.


Last edited by msc; 01-02-2011 at 05:45 PM.. Reason: Added link
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