BBB with Angstrom using PWM Input from Ultraonic Sensor

Ok, so I have a project that started out using an Arduino Mega. This project uses an Ultrasonic Sensor to give me distance measurement, and the sensor returns data over PWM. So, I need this project to be web connected and have some data logging, and instead of having an Arduino cobbled with something else and writing custom code and such, I went with the BBB. It’s running the stock Angstrom (with opkg upgrade completed) and I am trying to figure out how to get this sensor to interface with the BBB. preferably I would like to use the sensor as one would any GPIO by querying a file in the /sys tree, but the couple tutorials I have found have not worked and were for Ubuntu. While I prefer Ubuntu, I have been told that Angstrom has built-in support for PWM and has all the PRU items and dts overlays in place to do what I want, I just can’t figure it out for the life of me.

Not a tutorial but you may find this interesting. The gent coded the sensor PRU code in assembler.

I’m going to use a adafruit trinket and do measurements and then have the trinket send the results via serial to the BBB.