Scratchprogramming Asebascratch

Controlling Thymio from Scratch

This page presents the first implementation of Scratch for Thymio using AsebaScratch Alpha version.

A NEW complete version has been developed using the Official ScratchX eXtensions.

Asebascratch is a software link between Scratch 2 and the Thymio-II robot, with which Scratch 2 programs and sprites can interact with a Thymio-II or Wireless Thymio robot.

Scratch 2 is a visual programming system designed for children. A Scratch 2 program is comprised of sprites and a stage, each of which has a behaviour, a set of appearances, a set of sounds, and state variables. Sprites communicate using messages and shared variables, as well as their interaction on the stage. The behaviour of a sprite is defined by an independent program organised around event handlers for global events, such as key presses, mouse movements, and messages.

Combining a software helper with a special Aseba program defines a “Scratch personality” for the Thymio-II and allows it to be included as a sprite in a Scratch scene.

Installation Tutorial Video for the Alpha Version with Scratch 2 Offline Editor

TechyKids contributed an easy to follow Video Tutorial on how to get started with Scratch and Thymio.

Remember that with SCRATCHX you can use the Thymio programming within your browser.
check the NEW complete version developed using the Official ScratchX eXtensions.
In the ScratchX web page you will find all the instructions and also games and examples developed to demonstrate the usage of Thymio with Scratch.

Requirements for the Alpha version with Scratch 2 Offline Editor

1. Offline Scratch 2 from MIT
2. The asebascratch software (current release 0.7.3, for Windows and MacOS)
3. A Thymio-II connected by USB (cable or RF dongle) to the machine running Scratch 2
4. On Windows, the Aseba software that came with the robot

Quick start

1. Download and open the bundle for your operating system.
2. Double-click “Scratch2-ThymioII” to run the helper
3. Open one of the Scratch 2 examples

1. Plug in the dongle
2. Start the robot
3. Run the Scratch-Thymio helper
4. Run any of the Scratch examples
(click to see a video)


In order for the connection between Scratch 2 and Thymio-II to be useful in a teaching setting, we need to find the best match between their respective programming concepts. Note that many do not match: for example, Scratch 2 sprites have an absolute X-Y position and can move instantaneously, whereas the Thymio-II can only move by running its motors; Scratch 2 sprites can have many costumes whereas the Thymio-II can only change its lights; Thymio-II can continue to move even when the controlling program is busy, and so on.

This software tries to define a “Scratch 2 personality” for the Thymio-II that give sensible meaning to a sprite on the stage that can both react to the real world as seen by the robot, and react to other sprites on the stage (and transmit those reactions to the real robot).



A description of the implementation, the Aseba events added to the Thymio-II, and the REST interface used for communication can be found in Asebascratch README.

Scratch 2 high-level blocks and reporters

The new Scratch blocks added by the extension are described in Scratch blocks.

Simulating Thymio in Scratch

These simulations are intended for students who know Scratch and want to learn about Thymio and VPL, or, conversely, students who have experience with the robot and want to learn Scratch. The simulations are described in the document, while the Scratch projects themselves are available on the Scratch website in two "studios."

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