What is the best way to measure PWM signals ( pulseIn ) with the Arduino via a Raspberry Pi? I connected my Arduino Uno to my raspberry via USB serial. I'm able to read out both digital and analog pins of my Arduino using the Python nanpy library (v.0.8).
However, I can't find support for the pulseIn() function. It seems nanpy doesn't support pulseIn() at all.

What is the best way to measure PWM signals with the Arduino and forward the results to the Raspberry Pi? 

I am able to measure PWM using the Arduino GUI, however I would to take PWM samples at fixed time intervals over a long period of time and combine this data with other measurements that my Raspberry is making.I also tried pyFirmata, but it doesn't support pulseIn() measurements either.
Nanpy seems to have a CounterClass that does frequency measurements.

Or do you want to measure the PWM duty-cycle?