Lesson Crumble

Introduction to the Crumble Board for all ages

Updated January 2026

This is an educational resource for using the Crumble Board. This has been successfully delivered to students in Grade 2, 5 and 10. The time taken varies depending on the age and previous knowledge of Scratch.

Alternative Options: If you don't have Crumble boards, the BBC micro:bit is a popular alternative with similar block-based programming via MakeCode. The micro:bit has built-in LEDs, buttons, and sensors, making it excellent for beginners. The concepts in this lesson transfer well to micro:bit projects.

Lesson Structure

  • Starter
  • Task 1: Turning an LED on
  • Task 2: Blinking a single LED
  • Task 3: Alternate Blinking
  • Wrap Up

Kit List

  • Crumble
  • USB Cable
  • Crocodile Clips (for temporary projects)
  • Sparkles (Programmable LEDs)
  • Motors

New To Crumble

What is a Crumble and Understanding the Board

A simple-to-use microcontroller, a starter board for all. It can drive 2 motors forwards and backwards at variable speeds. It has 4 IO (Input/Output) pads which allow connections to switches, LDRs, low power LEDs and so on.

Download Software here

External Power

Battery or USB powered. The USB sends data and the board needs EXTERNAL power for the LED sparkles, motors and other crumbs. The on-board micro USB socket allows the Crumble to be programmed via a standard USB cable. The Crumble can be powered directly from USB, however, the motor driver and any external boards require an external power source of 4.5V to 5.5V (for example 3xAA batteries).

Teaching Tip: Some LED strips are 12V as they are designed for built-in projects - these will not work with the power pack included in the starter kit.

Keywords

  • Microcontroller - A small computer on a single chip
  • LEDs - Sparkles are programmable LEDs
  • Loops - Repeating code blocks
  • Delay - Waits (in seconds or milliseconds)

'0' - in computer science we start counting from zero

Main Activities

Task 1: Plug-in (10mins)

After downloading the Software, plug in the cable into the Crumble board. Be careful and ensure that the cable is plugged in the correct way around. Now connect to your computer.

Teaching Tip: The board does NOT light up to show that it is connected or powered via USB only. It only lights up the onboard LEDs if using an external power supply. Use the code blocks to create your program.

Task 2: Blinky (Hello World of the hardware world)

These small LEDs are connected to the section for motors which have the numbers 1 and 2 next to them. Program the board to turn on 1 LED and then turn it off again. Progress to looping the single LED and finally alternating between both onboard "motor" LEDs.

Teaching Tip: When teaching this, be careful to explain that you will need to use the motor block code as they control the LEDs that are built on the board. This can be confusing for younger learners.

For all programs we are going to use the following blocks: program start, motor, wait, loop

Question for Learner: Can you think of any other ways to flash the LEDs?

Task 3: Adding the Sparkles (15+ mins)

Wiring it Up

  1. Ensure that the CRUMBLE has an external power supply attached
  2. Connect just 1 sparkle to the crumble:
    • RED - Power
    • BLACK - Ground
    • GREEN - Data (this wire sends the code to the LED)

Code for Sparkle

  1. Use the block: set sparkle () to (colour)
  2. Use the wait() block
  3. Change the colour of the sparkle
  4. Click the coloured square box
  5. Select a new colour

Add Next Sparkle

  1. Connect the next Sparkle (1)
  2. Using crocodile clips, connect from Sparkle(0) to the next Sparkle(1) in a chain
  3. Connect: Ground, Power, Data

Additional Resources

Crumble Official Site Download Crumble Software