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How PhysiCode works

Children build a program out of real blocks they can hold, take one photo, and their robot runs it. No screens to type on, no accounts needed to start.

The three steps

  1. Build it

    Lay the printed blocks out on a table, left to right — always beginning with Start and finishing with End. Number tiles sit next to an action to say how far or how many.

  2. Snap it

    Open the app and take one photo of the whole row. Everything is read on the device itself — the photo is never uploaded, never stored, and never leaves the phone or tablet.

  3. Run it

    The app shows what it saw so a grown-up can check it, then sends the program to the robot over Bluetooth. The robot drives the program, and flashes a rainbow when it finishes.

A short clip of a program being built, scanned and run goes here.

Getting started

  1. Switch on the robot

    Turn on the micro:bit. It shows a P briefly to confirm it is running PhysiCode, then waits for a connection.

  2. Open the app

    Tap Open the web app below (in Chrome on Android, or another Bluetooth-capable browser). You can add it to the home screen and it works offline afterwards.

  3. Add a coder

    Create a profile for the child — just a first name, an avatar and a colour. Nothing else is ever asked for.

  4. Connect the robot

    Tap Connect and choose your micro:bit. The screen shows a tick when it is linked; the robot shows one too.

The missions

Five guided missions take a child from a single move to a full multi-step program.

MissionLevelBlocks it uses
Wake Up Robot1Start · Do · Move forward · End
Spin Around2Start · Do · Turn around · End
Go To Bed3Start · Do · Move forward · If · Do · Stop · End
Visit a Friend4Longer route — several moves and turns
Set The Table5The full set, combined

Children can also free-play: build any program they like and scan it, with no mission at all.

If something does not work

The app says it could not read the blocks

Get the whole row in frame, keep the paper flat, and avoid a shadow falling across it. Even, indirect light works best. Every block must be face-up and unobscured.

The robot will not connect

Check the micro:bit is on and showing P or a tick, that Bluetooth is enabled on the phone, and that no other device is already connected to that robot. Only one device can be connected at a time.

The robot moves the wrong distance

Distances are tuned per robot and per surface. A grown-up can adjust the calibration in Settings — carpet and hard floors behave differently.

Using it safely

The robot is a moving toy with wheels. Run it on a table or floor with clear space, keep fingers and hair away from the wheels, and keep an adult nearby while it is driving. Turn it off when play finishes.

Ready to try it?

The web app is free and works on a phone, tablet or laptop.

Open the web app