# 2WD explorer robot

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

## Roles

- Controller (qty 1): Raspberry Pi Pico 2 W <https://partsgraph.ai/catalog/parts/rpi-pico-2-w>
- Motor driver (qty 1): DRV8833 dual motor driver carrier <https://partsgraph.ai/catalog/parts/pololu-drv8833-carrier>
- Drive motors (qty 2): 150:1 micro metal gearmotor MP 6V <https://partsgraph.ai/catalog/parts/pololu-n20-150-mp6v> OR TT DC gearbox motor 200RPM 3-6V <https://partsgraph.ai/catalog/parts/adafruit-tt-motor>
- Wheels (qty 1): Wheel 32x7mm pair (for 3mm D shaft) <https://partsgraph.ai/catalog/parts/pololu-wheel-32x7> OR Orange & clear TT motor wheel <https://partsgraph.ai/catalog/parts/adafruit-tt-wheel> — sold as pairs; must match the chosen motor's shaft
- Third contact point (qty 1): Ball caster 3/8 inch metal ball <https://partsgraph.ai/catalog/parts/pololu-ball-caster-38>
- Chassis (qty 1): Mini 3-layer round robot chassis kit (2WD) <https://partsgraph.ai/catalog/parts/adafruit-3layer-chassis>
- Motor mounts (qty 1, optional): Micro metal gearmotor bracket extended pair <https://partsgraph.ai/catalog/parts/pololu-n20-bracket> — needed for the N20 option only — the chassis kit mounts TT motors directly
- Range sensor (qty 1): VL53L0X time-of-flight distance sensor breakout <https://partsgraph.ai/catalog/parts/adafruit-vl53l0x> OR Ultrasonic distance sensor HC-SR04 <https://partsgraph.ai/catalog/parts/sparkfun-hc-sr04>
- IMU (qty 1, optional): MPU-6050 6-DoF accel + gyro breakout <https://partsgraph.ai/catalog/parts/adafruit-mpu6050>
- Battery pack (qty 1): 4 x AA battery holder with on/off switch <https://partsgraph.ai/catalog/parts/adafruit-4xaa-holder>
- 5V rail (optional) (qty 1, optional): 5V 500mA step-down regulator D24V5F5 <https://partsgraph.ai/catalog/parts/pololu-5v-reg-d24v5f5>
- Power switch (qty 1, optional): Breadboard-friendly SPDT slide switch <https://partsgraph.ai/catalog/parts/adafruit-slide-switch>
- Breadboard (qty 1): Half-size breadboard <https://partsgraph.ai/catalog/parts/adafruit-half-breadboard>
- Jumper wires (qty 1): Premium male/male jumper wires 40 x 150mm <https://partsgraph.ai/catalog/parts/adafruit-jumper-mm> OR Premium female/male jumper wires 40 x 150mm <https://partsgraph.ai/catalog/parts/adafruit-jumper-fm>
- Standoffs and screws (qty 1, optional): Black nylon M2.5 screw / standoff kit <https://partsgraph.ai/catalog/parts/adafruit-standoff-kit>

## Constraints

- [supply-window] Motor 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-supply] The 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-peak] Motor 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-match] Wheels 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-voltage] The 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.
- [interface] Controller must expose PWM for the driver and I2C for the VL53L0X/MPU-6050 - the Pico 2 W exposes both.

Canonical: https://partsgraph.ai/catalog/builds/2wd-robot
All parts as JSON: https://partsgraph.ai/catalog/feed.json