Microcontroller - Automotive Timing Resolution Needed
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Microcontroller - Automotive Timing Resolution Needed
How much precision in mS or uS does a micro-controller need to properly control timing +/- .5deg. I'm trying to use a micro to delay the charge time on my Toyota COP's. But, according to my scope I'm firing the coils (going low) late by about .02mS.
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From: Chicago. (The less-murder part.)
Simple math, really.
7,000 RPM is 117 revolutions per second, or put another way, 42,000° of crank rotation per second.
So one degree of crank rotation is 1/42000 of a second, or about 0.024 milliseconds.
Thus, your 0.02ms error is slightly less than one degree. That's pretty trivial.
edit: Jason beats me to it.
7,000 RPM is 117 revolutions per second, or put another way, 42,000° of crank rotation per second.
So one degree of crank rotation is 1/42000 of a second, or about 0.024 milliseconds.
Thus, your 0.02ms error is slightly less than one degree. That's pretty trivial.
edit: Jason beats me to it.
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If it's late, probably fine because you can tune around that. If there's added jitter, then do not want.
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If it's ALWAYS 0.02 ms too late, you might be able to build some compensation factor into the software.
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