Love Hearts Lesson 2

In this lesson students consider how technology can help to record heart rates more accurately and design a prototype for a micro:bit heart rate monitor.

  • Global challenge
  • computing
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  • 年龄 9+
  • 60 分钟
  • MakeCode Editor


  • Computing: computational thinking: algorithms, logical thinking, decomposition, abstraction, iteration, loops, selection, variables, testing, debugging, evaluation
  • 科学:心脏
  • P.E.: The importance of regular exercise
  • PSHE: Healthy mind and body
  • Design & Technology: Product design

Skills: team working, creative thinking, designing, team working


It is assumed that you have first completed the Non-communicable disease introductory lesson and Lesson 1 of the Love Heart activity.


In this lesson students consider how technology can help to record heart rates more accurately and design a prototype for a micro:bit heart rate monitor. Some experience of writing algorithms using iteration, selection and variables is assumed, though extra time can be allocated easily if necessary.


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A the micro:bit heart rate monitor

  • Explain to students that they will be creating their own prototype of a heart rate monitor using micro:bit (slide 4) and introduce the criteria for their prototype (slide 5).
  • Give out rough paper to pairs or small groups of students and ask them to brainstorm initial ideas of what they will need to include in their prototype (explanation of prototype on slide 6 and some ideas on slide 7).
  • Discuss initial ideas as a class before explaining to students they will create a paper prototype (slide 8).

Creating paper prototypes

  • Give out large pieces of paper and pens (and micro:bits if using the boards) for students to design their prototype.
  • Invite them to sketch out their design first before moving on to the algorithm (or split these tasks if working in a group).

Algorithm design

  • Once students have completed their basic prototype, they can move on to writing the algorithm. There is a sample algorithm on slide 9 and you can recap iteration, selection and variables with students using slide 10 if needed.
  • 让学生在牛皮纸上写下他们的初始算法,以便在将最终版本转到纸质原型之前,对算法进行测试和问题排除工作。

Testing and debugging algorithms

  • Ask students to work with their peers to test and debug their algorithm, focussing on helping each other to write efficient algorithms and ensuring their prototypes meet the criteria.
  • Once they have a final, accurate version, they can add this to their paper prototype, highlighting where they have used iteration, selection and variables to create an efficient algorithm.

Showcasing paper prototypes

  • Invite students to stick their paper prototypes on the wall and present it to their peers, explaining their design, algorithm and how they worked out any problems. If time allows, invite other students to give constructive feedback (e.g. WWW / EBI).

Lesson wrap up

  • Ask students to think/pair/share why they have used iteration, selection and variables in their algorithms and what they have learnt from today’s lesson.
  • Explain that next lesson they will use their algorithms to create their micro:bit prototype and if you wish, revisit the learning objectives (slide 11).

Extension / homework

  • Students could research which heart monitors are most effective and why. They could write a ‘wish list’ of functions they would like their heart rate monitor to have which are not possible with micro:bit.



  • Encourage students to focus on a simple algorithm using everyday language rather than pseudocode if necessary. You could also give out text instructions and ask them to sequence them into the correct order for their algorithm.

Stretch & challenge:

Students can be challenged to create multiple, highly detailed, accurate algorithms for more advanced features they are including and making good use of iteration, selection and variables.

Opportunities for assessment:

  • Informal assessment during showcase (you could video each group) and through questioning.
  • 如果您愿意,可以对学生的纸质原型、算法进行更正式的评分,记得把重心放在对迭代、选择和变量这三点的有效使用上。
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