cattledog:
I think I understand.You want a new ignition pulse, on two pins to replace the current single output on pin 4.
Yes
It looks like we now get an output pulse on pin 4 of some length and some repeating frequency determined by the RPM setting. It sound like you want to change this to an output on two pins.
The length of the existing pulse is determined by barWidth I think. So the 2 new pulse array must replace >that in such a way that it tells the DAC to output a pos pulse and then after a time determined by barWidth >output a neg pulse, then no pulse until it repeats. i have to determine what the pulse width should be.
What I'm unclear of is how the two outputs to the DAC are timed. Is a +/- varying signal sent from the DAC to the module each cycle. Can you draw a timing diagram of how the 11 00 10 output states are sent to the DAC? Are they all sent in sequence during one output timing cycle?
In this simplest control of the DAC it has 3 states of output, 0 volt, pos volt, neg volt.
It would help me if you could draw a timing diagram of the desired output pulses.
attached is something that may help. MSB is DAC pin 5 and all others are 6 thru 12 tied together.
Can you explain about "barWidth". This variable does not appear in the previous code we worked on. What is it, and how does it relate to the timing of the 2 pulses.
It is the width of the bar that passes past the pickup coil. Some engines it is just a short bar and only >serves to make a short pulse where they are only interested in the positive component of the signal. These >generally have two pickup coils and two short bars. In this case I am only interested in one of the positive >pulses so I set the barWidth to small value. Other times the bar can be 60° long and the negative pulse is >at the beginning and then the positive is at the end of bar which has just one pickup coil. For this I set the >barWidth to a higher value, usually the bar length in degrees plus the base timing so 74 is a normal setting.
In this new mode of output to the DAC, will the the return pulse from the module and the reading on the pin 2 interrupt be unchanged?
I think the answer is yes.
Will the charge pulse code be unchanged?
Yes
It's been awhile
Yes for me also, I tend to forget a lot of what I have learned doing this!!
