Micro:bit sumo robot

Firmware and hardware design files for the TimeExpander.com Micro:bit based robot

The bot features two motor bridges, 3 x time of flight sensors, 4 x reflective object sensors and a GPIO Expander.

Toolchain for building the firmware is the mBed online compiler.

You can watch one of the demo state machines in action here: https://youtu.be/_6B225iNg58

Bill of materials

• 1 x Main PCB (https://github.com/hansj66/micro-bot/blob/master/Hardware/minisumo_v2.brd)
• 4 x line sensor PCBs (https://github.com/hansj66/micro-bot/blob/master/Hardware/minisumo_sensor.brd)
• 2 x Wheels (AliExpress)
• 2 x N20 motors (AliExpress)
• 2 x N20 motor bracket assembly (AliExpress)
• 3 x VL53L0X time of flight sensors on a carrier PCB (AliExpress)
• 1 x TCA9539 IO expander (Digikey)
• 1 x TXB0106PWR Bi-directional level translator (Digikey)
• 4 x QRE1113GR Reflective optical sensors (Digikey)
• 1 x 100uF aluminium capacitor
• 1 x 2x5 pin 2.54mm female header (Digikey)
• 1 x battery pack for 4x AAA (Digikey)
• 1 x JS202011SCQN slide switch (Digikey)
• 1 x SOT223 LM1117 3.3V regulator (Digikey)
• 1 x Mini caster assembly (AliExpress + 3D printed bracket)
• 2 x 3D printed spacers (between motors and PCB)
• 1 x 12 pin male breakaway header (Digikey)
• 3 x 6 pin RA breakaway header (Digikey)
• 1 x hook and loop tape (for attaching battery pack)
• 2 x 100nf capacitors (motor noise suppression)