Quantity   Component name
1 × Raspberry Pi 3 Responsible for running ROS nodes to interface with motors and sensors.
1 × microSD card for Raspberry Pi 3 Main system storage for Raspberry Pi 3.
1 × Battery output DC to 5V DC converter Power source for Raspberry Pi 3. I've had good experience with cheap MP1584 step-down converters from Amazon.
1 × Neato XV-11 (or similar) robot vacuum laser distance scanner Units salvaged from broken vacuums are available on eBay, search for "Neato LIDAR"
1 × Battery output DC to 3V DC converter Neato LIDAR's scanning motor requires 3V to spin at the correct speed. (3.3V is too fast.) Alternatively: use a DC motor speed controller to explicitly control spin speed of motor.
2 × DC motors with gearbox and quadrature encoder Gearbox ratio should be slow enough to allow Phoebe to craw cautiously at slow speed, but fast enough operators won't die of old age.
2 × Wheels that can mount to output shaft of gearbox Suggested: commodity wheels and tires from 1/10th scale remote control car market.
2 × Motor and wheel mounting bracket If not incorporated into 3D-printed chassis.
1 × Motor controller (Basic Micro Roboclaw 7A, or similar) Deliver battery power to drive 2 DC motors, and also read quadrature encoders associated with each motor.
1 × Caster wheel Can be salvaged from broken office furniture
1 × Battery