Navio2 - RPM sensor input

I have a RPM sensor with 3.3V pulse output. How can i connect this to Navio2? I see 2 spare IO of F4 MCU, does Navio2 have ability to accept the RPM input, or i have to use the RPI2 GPIO instead ?. I want to monitor the motor speed on my GCS.

Thanks.

Peter, there is no way at the moment to read PWM. Navio2 has 2 spare ADC ports and if you filter PWM with a capacitor, you will be able to measure RPM through the ADC.