Build yours at home

Your first real robot

What we're doing

Build a real robot with all five parts from the levels: power, muscles, senses, brain and body. Then type in the Level 4 rule card so it stops before a wall.

Drag to turn

About 1–2 hours.

Goes with these lessons

Get these parts

Makeblock mBot (classic), Bluetooth version, about $70. Get the Bluetooth version to use a tablet or phone; the 2.4G version needs a computer. (Makeblock or robot shop)
4 AA batteries (household)
1 CR2025 coin battery for the remote (not in the box) (household)
A tablet, phone or computer with the free mBlock app (household)

Keep it safe

Battery power only, never household power. Use AA packs matched to the parts, not a 9V battery. A grown-up connects and disconnects the pack. Stop immediately if any part warms. Never join the pack's two metal ends: the wires can get hot. Coin cells stay with grown-ups, locked away. CPSC warns a swallowed button or coin cell can burn through a child's throat in about two hours; suspected swallowing needs emergency medical care immediately.

A grown-up fits the remote's coin battery and keeps spares locked away.

Steps

1
Build the robot
Build it together from the instructions in the box. It takes 15 minutes to an hour, and the screwdriver is in the box. As each part goes on, name its level: battery pack (Power), two motors (Muscles), echo sensor (ultrasonic sensor), line sensors (line follower sensor) and light sensor (light sensor) (Senses), the board (Brain), frame and wheels (Body).
2
Put in the batteries, switch on and drive it with the remote from the box.
3
Open mBlock and connect to the robot over Bluetooth.
4
Type in the rule card 'If something is close, then stop' as blocks: repeat forever, if the distance is less than 15 cm, stop, otherwise go forward. Keep the rule card next to the screen and read the blocks out loud as you stack them.
The rule card as blocks
```
Rule card:   IF SOMETHING IS CLOSE  THEN  STOP

Block stack: repeat forever
               if distance is less than 15 cm
                 stop
               otherwise
                 go forward
```
5
Put the robot on the floor facing a wall and run it. It stops before the wall.
6
Fix the robot
Unplug one motor's cable from the board and run it again. It turns in circles. Which part is missing? Plug it back in: fixed.
7
Switch off. Next, plan one new ability on Your robot, your idea.

Talk while you build

Which part tells the robot the wall is close?
What does its rule tell the motors to do?

Spot it at home

A robot vacuum: battery, motors, bump and cliff sensors, a brain, and a body.

What job does each part do in a robot vacuum?

A flashlight that won't turn on: batteries first, then the switch, then the bulb. A TV remote that stops working.

The remote stopped working. What would you check first, second and third?

About our drawing

The drawing labels one can 'shout' and one 'listen'; we haven't confirmed which side is which on the real module. The motor insides are an illustration.

Why the mBot, and other options

Why this one: every part maps to a level. Battery pack (Power), two motors (Muscles), echo sensor, line sensors and light sensor (Senses), the brain board (Brain), frame and wheels (Body). It has spare ports for adding one more part later.

If you'd rather: micro:bit + Maqueen Lite, about $55, the cheapest, with the same blocks many schools use. Ozobot Evo, about $175, rules drawn with markers and no screen, but nothing to build. Hummingbird Bit, about $230, servos, lights and sensors you attach to cardboard, best for open-ended design later.

Ages 8+, younger with a grown-up. Prices checked Oct 23, 2026; they change, so check before buying.

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