Quote:
Originally Posted by jackbauer
Something i've wanted to do for sometime has been to add motor rpm feedback to the controller. Does the micro have sufficent resources left to do this in software? I'm playing with a little frequency detection circuit based on an lm2917.
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I use the LM2917 and part of a LM339 to trigger my rpm warning (set by 10 turn pot ) for 6000 rpm. there is option for shut down or rpm limiting on my PCM replacement board along with the computer voice cockpit warning in the EV. Seems to work well - I just will not drive it in the salt infested roads ! I buffer the 6 lobe pickup, on the tail-shaft, with a 4093B quad Schmidt-trigger to it and the speedometer input via a driver transistor. It gives me accurate rpm on the speedometer and a warning of excessive rpm..... I did feed it to an Arduino and read voltage to rpm in my version 2 PCM. It did not take much in the line of code to get it working ... I think you may have seen it on another forum.