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
Print lesson
  • Edades 9+
  • 60 minutos
  • MakeCode Editor

Curriculum links

  • Computing: computational thinking: algorithms, logical thinking, decomposition, abstraction, iteration, loops, selection, variables, testing, debugging, evaluation
  • Science: The heart
  • 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.

Teacher Guide

Open Open teacher resources


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.
  • Ask students to write their initial algorithm on rough paper so they can test and debug it before transferring a final version to their paper prototype.

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.
  • More formal assessment if wished, of students’ paper prototypes, algorithms, focussing on the efficient and effective use of iteration, selection and variables.
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