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Topic: Mistake inPWM tutorial (Read 3 times) previous topic - next topic

BetaTheta

Hi,

I was going through the PWM tutorial:
http://arduino.cc/en/Tutorial/PWM

Just want to make sure, but shouldn't a 25% duty cycle be AnalogWrite(63) instead of AnalogWrite(64)?

My understand is that AnalogWrite(0) should really be 1/256th duty cycle, but the program cheats and has it be 0% duty cycle. Nevertheless that should still make 63 be 1/4th duty cycle, right?

Jantje

IMHO
AnalogWrite(x) is 100 * x / 255 % duty cycle
=>
AnalogWrite(0) is 100 * 0 / 255 % or 0% duty cycle
AnalogWrite(255) is 100 * 255 / 255 % or 100% duty cycle
AnalogWrite(63) is 100 * 63 / 255 % or 24.7% duty cycle
AnalogWrite(64) is 100 * 64 / 255 % or 25.09% duty cycle
So I think 64 maches better to 25% than 63
Best regards
Jantje
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