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Old 09-25-2010, 11:40 PM   #3804 (permalink)
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The values of R10 and R8 are important, because the formula for the voltage at the microcontroller is:

5v*R10/(R8 + R10)

R4 plays no role whatsoever in the voltage at the pin to the microcontroller. That was really confusing to me for a long time. The reason is, as best as I understand it, inside the microcontroller on an input pin is really high resistance. So, a 1 Ohm resistor or 4.7kOhm resistor on an input pin has almost no voltage drop. I have no idea what's going on inside there, but that's the affect.

So, with R8 = 2k and R10 = 4.7k, the voltage at the throttle pin isn't about 3.5v?
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