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Read PWM signal


#1

I have a RC reciever from my model aircraft and I would like to use that with FEZ Domino to control a robot. In the beginner book I saw only tutorials about how to generate PWM signal not read it.
Can someone please point me in the right direction?


#2

I’m doing this with my UAV project. Chris posted his version to Fezzer: http://www.fezzer.com/project/150/servo-signal-decoder/

Basically, you connect the signal to an interrupt port. You wire up an event to catch the edges (low->high and high->low). You record the time for low->high and on high->low you time the difference and that’s your value. It’s actually very accurate because Fez/MF will timestamp the interrupts with exactly when they occurred.


#3

Thanks a lot:)


#4

If it helps anyone with this topic…

If you calculate what resistance and capacitance required to stabilise the frequency you can just read it from the analogue port…

I have a very slow frequency of 100 hz… with a 100uf cap and a 10k resistor I get a pretty stable voltage proportional to the pulse width. I use it with my wind speed device…

Cheers Ian