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Ozobot Colour Coding Challenges

Ozobots are small line-following robots that respond to coloured codes by changing their direction of movement, their speed, or the colour of the LED on top

This series of challenges emphasizes the following Computational Thinking skills:

  • Evaluation – determining the optimal way to use lines and colour codes to communicate with the ozobot by assessing and debugging each attempt
  • Abstraction – representing complex behaviour as a series of coloured squares
  • Logical reasoning – “if I use this code, the ozobot will behave this way”
  • Decomposition – in the final challenge, a complex path must be constructed from simpler parts.

Objectives

  • Using markers and paper, students will progress through a series of challenges that explore how to use simple colour codes to program a small robot to respond in a variety of ways.

Materials

  • General supplies:
    White paper (at least a few sheets per group of students)
    Chisel tip markers in black, red, green, and blue (make sure the markers are quite bright as darker colours will not be read by the Ozobots – we recommend the Ozobot markers or Crayola chisel tips)
    Charging cords or charging hub.

  • Per group of 2-3 students:
    Ozobot Bit
    Download Color Code and Line Drawing Tips
    Download Ozobot Colour Coding challenge cards

Key Questions

  • Which challenge was easy?
  • Which challenge was difficult?
  • Did Ozobot always do what you expected?
  • What advice would you give a “newbie” about drawing codes?

What To Do

Ozobot Safety Notes:

  • No water/drinks near Ozobots
  • No running near or with Ozobots
  • Lift the Ozobot up when moving it. Do not push Ozobots along table/carpet (it will break the Ozobot motors) or allow them to “spin their wheels” while running into the wall, etc.

Advance Preparation:

  • Ensure Ozobots are fully charged at the beginning of the activity. Ozobots take about 30-40 minutes to fully charge.
  • Have spare sheets of paper available to hand out. Encourage trying multiple things on one sheet of paper.
  • Calibrate each ozobot: Have the sheet with the black calibration dot ready. Hold the power button on the Ozobot down for two seconds until the top LED flashes white. Quickly place the Ozobot in the middle of the black calibration dot and let go. If the calibration is successful, the Ozobot will move and then blink green. Start over if the robot blinks red. Robots need to be calibrated once at the beginning of each session
  • Students should work in pairs or groups of three.
  • Each pair or group should start with one Ozobot, colour code sheets and calibration dot, a piece of white paper, and one black marker.

Activity: 

Hand out the Ozobots and ask students to locate the following features: on/off switch, optical sensors, wheels.
Tip: Introduce colours after students are comfortable with drawing lines. Colour codes have to be added as an interruption to the black line, they cannot go over the top of a black line.

 

Hand out the first two challenge cards to students.

  • Challenge 1  Follow the Line: Draw a path for your ozobot to follow
  • Challenge 2 – Speed up or Slow Down: change the speed of your ozobot using one extra colour

Once students have successfully demonstrated their solution to Challenge 2, you may wish to allow the groups of students to continue at their own pace

  • Challenge 3 – Right or Left: Tell your ozobot which way to turn at an intersection.
  • Challenge 4 – Stop! Tell your ozobot to stop without touching it.
  • Challenge 5 – Crazy Path: Create a path with at least four codes

Extensions

Other Resources

Science World  |  Field trip workshops and outreach programs  | Tech Up

Ozobot | Colour Coding Tips  & Ozobot Colour Coding challenge cards

Ozobot | more challenges and games for ozobot

Ozobot has a thriving educator community and plenty of resources