It should be possible to connect the 3pi and XBee to an Arduino Mega and control the 3pi from the it. You can use the same serial communications pins (PD0 and PD1) to connect your Arduino to the 3pi. You might find our serial slave program helpful for controlling the 3pi with the Arduino. With the serial slave program loaded onto the 3pi, you can send commands to control various features of the 3pi. You can find more information about this in the “Serial slave program” section of the 3pi user’s guide. (We also have a Spanish version of the user’s guide that a customer made.)
Is the white line on a dark surface? If so, the only change you should have to make to the example 3pi code to follow a white line is replacing the read_line() function calls with read_line_white(). You might find this forum thread on the topic helpful.
- Jeremy