PWM input?
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Is there a straightforward way to read a pwm signal as an input on the duet 2 wifi + duex with rrf? I know I can probably filter it down to analog and utilize the a2d converter but that sounds rather roundabout when I have a solid pwm input signal to begin with, and I'm not sure if there will be artifacts from the ripple from the pwm lining up with sampling frequency creating a beat frequency. I'd rather avoid that whole possibility.
I will need about 8 inputs but less would still be useful for development, and it would be slightly preferable to use the thermistor inputs but that is not a requirement. I don't want to do serial as I really only need to send one continuous variable and pwm should be solid over less than ideal wiring.
One signal i would like to feed it into is the temperature pid loop replacing the thermistor. the other is for a sensor and as long as I can query its current value via gcode I'm good.
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@john-meacham
RRF is pretty good at spitting out all sorts of signals, but reading data is not it's strength. (eg. SPI port can read some bytes, but they only echo on the web interface instead of filling a variable)
So I tried to A/D convert a PWM sensor output, but it failed greatly. Even 10-fold oversampling/averaging didn't help.You'll have to write your own RRF sensor version I'm afraid
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Can you give some more details on what you're actually trying to do?
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@phaedrux I am making a small board that will fit on the hotend and take care of reading the pt100 and turning on the heat sink fan when needed (removing the need for the duet to care about that fan or run wires to it) as well as normalizing the pwm signal for the part cooling fan and bumping up the pwm frequency fed to the fan to something it can deal with and utilizing the tach input from the fan for feedback.
I'd still need to feed the temperature back to the duet and the easiest way would be to send a pwm signal up the thermistor line.
The other pwm input pins were for a different project where I wanted to send force feedback to the duet for a dimensional probing toolhead with a load cell. but we can ignore that for now, I was just hoping a solution for that would fall out of the pwm temp feedback.
