User Manual

m3pi charge port.

The LEDs are evenly distributed both radially and horizontally, which means they can conceivably be

used for persistence of vision displays when the m3pi robot is spinning in place or driving straight. In

practice, we have found that the robot does not drive fast enough in a straight line for the naked eye

to perceive persistence of vision (though it could still work if you use a camera to take a picture with

a long exposure time as the robot drives), but it does spin fast enough when rotating in place for the

naked eye to perceive persistence of vision displays (see the pictures below).

Pololu m3pi robot writing “HELLO”

with its eight mbed-controlled LEDs as

it spins in place (persistence of

vision).

Pololu m3pi robot writing “HELLO”

with its eight mbed-controlled LEDs as

it spins in place (persistence of

vision).

4.f. Charge Port

The m3pi expansion PCB has a two-pin charge port in the front-left

corner of the robot that can be used to recharge your m3pi robot if

you are using rechargeable batteries. The fully-assembled m3pi

robot ships with a female 0.1″ header soldered into this port; the

m3pi expansion kit includes the header but it is not soldered in. The

charge port provides a direct connection to the batteries and can be

used with a charger capable of charging four NiMH or NiCD cells

(depending on what you’re using) in series. The iMAX-B6AC

charger [https://www.pololu.com/product/2588] works well for this

purpose; other such chargers are readily available in hobby stores

for charging electric model airplane battery packs. The positive side

of the batteries is labeled on the charge port by a white “+” on the

PCB silkscreen.

4. The Expansion Board in Detail Page 33 of 39