[Diy_efi] 60-2 crank sensor algorythms

[Brian Sidebotham]

Hi, Thanks for that.

I think I will do a small dedicated processor for this task to interrupt 
the main processor at the first missing tooth, and use a counter 
and another timer to keep track of the engine angle....

Thanks for the pointers.. I'm just building a small CAS output 
simulator now to check my hardware with. Should be interesting.

Thanks, Brian Sidebotham.


> Hi,
> 
> the algorithm is quite straight foward:
> 
> at every positive flange of the tooth, you get interrupted (by the uC
> pin input). Then you're determining the time for that tooth (by a
> timer or whatever is appropriate on your micro) and store the result
> in an array (with the size of three). Before storing it, you need to
> shift the current array contents by one.
> 
> The algorithm then to detrmine, if the missing teeth have been passed
> is very easy:
> 
> your array contains the times for the last three theeth t1, t2, t3
> 
> if t2 > t1 + t3 then the missing teeth is the overlast one, which is
> ok. if t1 > t2 + t3 then the gap was detected one tooth to early and
> you can run a compensation algorithm if t3 > t1 + t2 then the gap is
> detected one tooth too late and you can run another compensation algo.
> 
> Once you detected the gap, you can reset your main timer (that
> represents the crank angle) to zero and reload the timers, that
> control the inginition and injection pulses.
> 
> I have to admit, that I'm working with Infineons TriCore, that has
> plenty of hardware timers linked to each other, which makes things
> easier. But implementing that in software is also not a big deal.
> 
> Ciao
> Markus
> 
> 
> 
> Brian Sidebotham schrieb:
> > Hi all,
> > 
> >  I'm currently worked on a few bits that require me to
> > work with a 
> > bosch 60-2 crank angle sensor. Now the EFI332 project
> > uses the 
> > TPU section of the processor which looks like a fine
> > idea, but the 
> > code does not seem to be available from the site anymore
> > :(
> > 
> >  Anyway, I am using a different make of processor, and I
> > would like 
> > to get crank angle information without the need for a
> > TPU, but 
> > using standard timers, and external interrupts, etc.
> > 
> >  I wouldn't even mind doing a dedicated processor that
> > finds the 
> > two missing teeth, and outputs them so that they could
> > cause an 
> > interrupt on my main processor, and the CAS signal can be
> > 
> > connected to a timer input on my main processor to keep
> > track of 
> > engine angle.
> > 
> >  What has everyone else done?
> > 
> > Cheers, Brian Sidebotham.
> > 
> > 
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> >
> 



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