| Tropical Boy |
it seems all good....
whats the problem? |
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| sparkycivic |
soo, this thing divides the sensor pules to drive the megasquirt? how does it know what to divide by?
this might be in the pdf, but i was unable to read it. |
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| Adam |
I dont see the proper amount of dilithium being routed to the flux capacitor!!
j/k:p :p |
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| ae1969 |
quote:
Originally posted by sparkycivic
soo, this thing divides the sensor pules to drive the megasquirt? how does it know what to divide by?
this might be in the pdf, but i was unable to read it.
Correct Sparky!
Its built in to the chip. It was made to do this. You can divide by10,9,8,7,6,5,4,3,2 counters...
The dilemna with my car is that we a have a large # ring gear 132. The limitations on megasquirt is ~63 teeth....
So we have to rig something to divide the signal .....
Now we have two points that provide signals on my car...
1- reference sensor (One pin on the flywheel)
2- Ring gear teeth 132 divide by 4.... we will get a 44-1 wheel (well kinda)
NOW questions I have to verify.... So if someone could PLEASE read the specs on the chip. :)
1. The refence sensor feeds #15 on the chip. and the sensor generates a peak to peak voltage of >2.0 volts.
Is that enough to drive a signal into the chip? I am not sure reading the schematics on the chip?
2. The speed sensor (ring gear) feeds #14 same thing as #1. Is 2.0 volts peak to peak enough?
Do we need transistors to amplify the signal is 2Volts enough? |
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| sparkycivic |
you wanted to divide by 4?? you're set up to divide by 3 according to the diagram... you shouldnt need the other IC to divide by 4
also the Q's are mixed up in the labels just a pointless observation.
the input voltages should be fine as far as I can tell anything between 1 and 12 volts should work for signal input..
by the example operation chart, it looks like "reset" needs to be pulled down for the unit to operate.
132/4 is 33 pulses/rev
132/3 is 44 pulses/rev
whichever the megasquirt is expecting... i don't know. |
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| ae1969 |
quote:
Originally posted by sparkycivic
you wanted to divide by 4?? you're set up to divide by 3 according to the diagram... you shouldnt need the other IC to divide by 4
also the Q's are mixed up in the labels just a pointless observation.
the input voltages should be fine as far as I can tell anything between 1 and 12 volts should work for signal input..
by the example operation chart, it looks like "reset" needs to be pulled down for the unit to operate.
132/4 is 33 pulses/rev
132/3 is 44 pulses/rev
whichever the megasquirt is expecting... i don't know.
Yes sorry ......... it is 3 I am dividing by. Hence the use of a 4011 to accomplish this.
Thanks sparky ... you have cleared up a few things.
I think this will work. I guess we will know if it actually starts.......
Highly appreciate it.... I may have more questions for you as we go along. :)
Hey Sparky........... would there be a good way to bench test this gizmo???? I have an oscilloscope........ and the sensors.... I could make a wheel to see if it works? I just want to see if the output going to the megasquirt is in fact what I am hoping to see. :)
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| sparkycivic |
| spin the toothed wheel with a drill and hold the sensor real close... that might work, but that sounds like a big pain in the ass just to hook up. a signal generator would be a real nice thing to have right about now... :P |
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