Robot Build Guide

Welcome

This guide will walk you through building and wiring a compact robot step-by-step. Use the arrows or numbered navigation to move between stages. At any time, you can scroll within a step to see more detailed instructions and images.

What you'll need: various tools, fasteners, and your robot kit components. Refer to each step to see exact parts and diagrams.

When you're ready, click the arrow to begin with the first assembly step.

Step 1: Wheel and Motor Assembly

Mount the motor to the bracket using two M3 screws. Secondly, press in two M3 Square nuts (if they aren't already in place). Finally, press the wheel onto the motor shaft.

Exploded view of wheel and motor assembly view 1

Exploded view of wheel and motor assembly view 2

Tip: The other motor assembly should be the MIRROR of the first you make; ensure the bracket and wheel get placed on the opposite side of the motor.

Step 2: Ultrasonic Sensor Assembly

Insert the ultrasonic sensor into the sensor mount. Make sure both "eyes" face outward and the sensor is pressed in as far as it can go.

Ultrasonic sensor Exploded view of ultrasonic sensor assembly

Note: The sensor only fits one way—check pin orientation before proceeding.

Step 3: Front Skid and QTI Sensor Array Assembly

Attach the QTI reflectance sensor board to the bottom of the front skid using four small standoffs. Then, mount the entire skid assembly to the front of the robot chassis.

Reminder: Route the QTI wires upward through the slots in the chassis for easy connection later.

Step 4: Main Assembly

Add left and right wheel assemblies to the main chassis plate.

Secure the Crickit board using M3 spacers and screws.

Attach the front skid with QTI sensor as shown previously.

Step 03 - Attach Front Skid and QTI Sensor Array

Mount the battery holder centrally between the wheel brackets.

Insert the ultrasonic sensor into its slots on the front face.

Step 05 - Connect Ultrasonic Sensor Assemblies

Attach the neopixel strip and snap-fit the bracket in place.

Finally, plug in the Micro:bit into the Crickit edge connector.

Step 07 - Plug Micro:bit into Crickit Board

Check: All connectors and mounting points should be snug but not over-tightened.

Step 5: Wiring

Left Motor

Motor 1 connections (screw terminal ×2)

Right Motor

Motor 2 connections (screw terminal ×2)

Ultrasonic

DON'T WIRE this time — we need a different sensor type for the Micro:bit 3.3 V.

Line Sensors (Front Skid)

Each of the five sensor middle wires (OUT) will connect to the signal pins on the Crickit board. If you are looking at the skid from the front:

The leftmost OUT → signal 2
The middlemost OUT → signal 4
The rightmost OUT → signal 6

All the GND connections on the sensors will connect to GND on the Crickit board using the 5-to-1 wire harness (black or brown).

All the VCC connections on the sensors will connect to 3.3 V on the Crickit board using the 5-to-1 wire harness (red).

Hint: Use color-coded wires where possible to avoid confusion during troubleshooting.