User Manual

Pololu m3pi robot with mbed and
Wixel modules socketed.
Pololu m3pi robot with mbed and XBee
modules socketed.
The m3pi expansion PCB connects mbed pins P9 and P10 directly to the serial RX (PD0) and TX
(PD1) pins of the 3pi base, respectively. It also connects mbed pin P8 to the 3pi’s reset pin (PC6)
through a level-shifting MOSFET. The level shifter also acts as an inverter, so driving P8 high resets
the 3pi. The 3pi serial and reset pins can also be connected directly to a socketed Wixel or XBee via
a set of three jumpers, which allows you to use the 3pi as a wireless serial slave without an mbed, or
you can program the Wixel to serve as the robot’s main controller. The following diagram shows how
the mbed and jumpers connect to the 3pi robot base:
Pololu m3pi User’s Guide © 2001–2017 Pololu Corporation
4. The Expansion Board in Detail Page 25 of 39