These are the Arduino files that I was able to run successfully on the Arduino Leonardo for use with the PA-12 actuator; most of them are based heavily on the example code found in the PA_12 Arduino library.
The only documentation for the API that I could find is at (this link)[https://www.progressiveautomations.com/blogs/products/getting-started-with-arduino-and-pa-12], and is somewhat lacking. I recommend reading through the library.