Demo catalogue / build

2WD explorer robot

A two-wheel differential-drive robot that avoids obstacles: the classic first build, specified entirely from machine-readable part records.

Agent-readable: markdown · machine feed: feed.json

Roles and candidates

Role	Qty	Candidates
Controller	1	Raspberry Pi Pico 2 W£6.70
Motor driver	1	DRV8833 dual motor driver carrier$10.95
Drive motors	2	150:1 micro metal gearmotor MP 6V$23.95TT DC gearbox motor 200RPM 3-6V$2.95
Wheels	1	Wheel 32x7mm pair (for 3mm D shaft)$4.45Orange & clear TT motor wheel$1.50 sold as pairs; must match the chosen motor's shaft
Third contact point	1	Ball caster 3/8 inch metal ball$2.95
Chassis	1	Mini 3-layer round robot chassis kit (2WD)$24.95
Motor mountsoptional	1	Micro metal gearmotor bracket extended pair$2.95 needed for the N20 option only — the chassis kit mounts TT motors directly
Range sensor	1	VL53L0X time-of-flight distance sensor breakout$14.95Ultrasonic distance sensor HC-SR04$5.25
IMUoptional	1	MPU-6050 6-DoF accel + gyro breakout$12.95
Battery pack	1	4 x AA battery holder with on/off switch$2.95
5V rail (optional)optional	1	5V 500mA step-down regulator D24V5F5$8.95
Power switchoptional	1	Breadboard-friendly SPDT slide switch$0.95
Breadboard	1	Half-size breadboard$4.95
Jumper wires	1	Premium male/male jumper wires 40 x 150mm$3.95Premium female/male jumper wires 40 x 150mm$3.95
Standoffs and screwsoptional	1	Black nylon M2.5 screw / standoff kit$16.95

Constraints an agent must satisfy

• supply-windowMotor supply must sit inside the driver's corroborated range (2.7-10.8 V). A 4xAA pack is 4.8 V NiMH or 6 V alkaline - both inside it.
• controller-supplyThe same pack must sit inside the controller's VSYS window (1.8-5.5 V corroborated). NiMH at 4.8 V fits; 6 V alkaline exceeds it - use NiMH, or add the 5 V regulator.
• stall-within-peakMotor stall current must not exceed the driver's peak per channel (2 A corroborated). N20 stall 1.6 A and TT stall are inside it.
• shaft-matchWheels must match the motor shaft: 32x7 mm wheels fit the N20's 3 mm D shaft; the orange TT wheel fits the TT motor's dual-D shaft. Cross-pairing does not fit.
• sensor-voltageThe VL53L0X breakout accepts 3-5 V (corroborated) and is the safe choice on a 3.3 V controller. The HC-SR04 wants 5 V - marginal on a 4.8 V NiMH pack; prefer the VL53L0X or add the 5 V rail.
• interfaceController must expose PWM for the driver and I2C for the VL53L0X/MPU-6050 - the Pico 2 W exposes both.