[snekiam]

What are you using vision for if it doesn't go through the roborio at some point? If its just to display on your driverstation, then that is fine, but why do you need a pi for that? Anything other than the roborio directly controlling a motor is illegal, so you will need to have some interaction between the roborio and the pi. If you are looking to feed info about the images from the pi to the roborio, you could use UART or pynetworktables, but I'm not sure what else.