Hello! I am trying to add a PING ultrasonic sensor to my 3pi I have the signal pin connect to PD1 but I have no idea what to do for Ping part of the code. Please Help. 
Hello.
Parallax gives example code for controlling the Ping in BASIC. The easiest thing to do would probably be to translate that code into C. By the way, Googling for “ping AVR” seems like it turns up some code as well.
If you write some code that you are unsure will work, feel free to post it and I can take a look.
- Ryan
Thanks RyanTM.