Scratch Arduino Extension

View project on Github

Getting Started

1. Upload the StandardFirmata firmware to Arduino

  1. If you haven't already, download and install the Arduino software (Windows or Mac instructions)
  2. Connect the Arduino board to your computer's USB port
  3. Launch the Arduino software
  4. Go to File > Examples > Firmata > Standard Firmata
  5. Select your Arduino board from the Tools > Board menu
  6. Select your serial port from the Tools > Port menu.
    On Mac, it's something like /dev/tty.usbmodem-1511.
    On Windows, it's probably the highest-numbered COM port.
    (Or unplug the Arduino, check the menu, and then replug your Arduino and see what new port appears.)
  7. Click the upload button

2. Install the Scratch Extensions Browser Plugin

You will need to use the Firefox web browser for this extension to work

Download and install the Scratch Extensions Browser Plugin for "other web browsers"

*There is an issue with the Chrome version of the Scratch Extensions Browser Plugin that is preventing the Arduino extension from working properly in the Chrome web browser

3. Load the Arduino extension on ScratchX

Launch the extension by going to the following URL:

NOTE: On Firefox, you might see "Allow to run "Scratch Device?". Click "Allow...".

You might see another message, "Allow to run plugins?". Set both Adobe Flash and Scratch Device to "Allow and Remember" and click okay.

4. Waiting for the green light

When you see the indicator light in the "More Blocks" tab turn green your ready to start using the extension!

Green indicator light

See the section on the homepage for Supported Languages, for information on alternate block tanslations.

Now take a look at the Scratch Blocks and the example projects to learn how to use the extension.