I'm guessing this might be code Xanawatt is referring to?
https://github.com/Xanawatt/PixyI2C
Just a guess..
I'd like to see more info how you or anyone else actually connected the pixy to the hw. Wiring info and/or pics of what you did would be really helpful. We are trying to figure out which method to use to connect pixy to roborio. I think our choices are(in order of preference) i2c, uart serial, or plain ol analog/digital.
Related, i also found a few repos that contained what looks like uart serial code. This is just one example:
https://github.com/Zero2848/PixyCamTest