InputTrigger/NissanTrigger (2010-12-30 09:38:33)

For the Nissan CAS trigger (360 pulses) 3 possible solutions (one working, one should be easy and one hard)

Current solution is a 24+1 slot trigger wheel as described here: VehicleFitment/Nissan

We have a number of cars running on these trigger disks.


With leaving the 360 impulse disk, a hardware divby8 divider can help. We have divby8 implemented with HCF4024 circuit (originally for high toothcount ABS wheels). Since this circuit has (active-high) reset input, this can be useful to make a precise 45 pulse toothtrain from the 360 tooth.


Alternative solution would be software divide by the main processor. The processor is definitely capable. But unfortunately we have some tasks in interrupt that would need to be rewritten. (not the trigger input capture interrupt, but other interrupts that could interfere). This has been evaluated but found to be too much work that would delay other developments unacceptably.


See also