3pi Expansion Kit without Cutouts - Black
This kit gives you everything you need to add a second level to your 3pi robot. In this version, the LCD pins are brought up to the expansion board from the base via extended headers for your own custom use. This black printed circuit board matches the color of the 3pi and can also serve as a general-purpose round prototyping board.
This kit includes a round printed circuit board (PCB) with holes spaced on a 0.1″; grid, one extended 2×7 male header, two extended 1×2 male headers, one 2×7 female header, two 1×2 female headers, four 22 mm (7/8″) nylon spacers, four 1-1/4″ #2-56 screws, and four #2-56 nuts.
The expansion PCB matches the diameter of the 3pi chassis and mounts just above the tops of the wheels using the four included screws and spacers. Once assembled, the PCB has electrical connections to the base that allow you interface your own electronics with the 3pi robot, which is sold separately. These connections give you access to the ATmega168’s LCD pins, ISP programming pins, and free/jumpered pins, as well as to the three on-board voltages: VBAT (battery voltage), VCC (regulated 5 V), and VBST (regulated 9.25 V that is supplied to the motors). Additionally, the expansion PCB connects to the base’s power button and battery charge port, allowing you to add your own power buttons and charge ports.
The expansion PCB is designed to provide plenty of prototyping space for your components. It has room for two 0.6" 40-pin DIP (dual in-line package) components, such as the ATmega32 in the picture below, or for numerous smaller DIP components. The prototyping space extends all the way to the edge of the PCB, allowing you convenient points to mount a variety of sensors such as bumper switches and range-finders. The silkscreen shows how the pads are connected; the electrical connections are on the bottom side. You can cut the copper traces on that bottom side (with a sharp knife or a small rotary tool cutoff wheel) if some of the pre-made connections interfere with your desired layout.
Note: This expansion kit replaces the 3pi’s LCD.