OVERVIEW

Activity Overview:

In this lesson, pupils develop their understanding of the micro:bit by using the buttons and sensors on the device to make different images display. Pupils are introduced to the concept of a variable to store data, then create a program to alter the value of a variable using the buttons and sensors. Pupils go on to create a ‘push the button’ game, where they race against another player to see who can press the button the fastest.

Meta description

• Subject Area: Computer Science
• Grade Level : K-2
• Computer Science Domains:
  • Computing Systems
• Computer Science Principles:
  • Fostering an Inclusive Computing Culture, Collaborating Around Computing, Recognizing and Defining Computational Problems
• Materials:
  • Micro:bit
• Considerations: +

Lesson Plan

Overview

In this lesson, pupils develop their understanding of the micro:bit by using the buttons and sensors on the device to make different images display. Pupils are introduced to the concept of a variable to store data, then create a program to alter the value of a variable using the buttons and sensors. Pupils go on to create a ‘push the button’ game, where they race against another player to see who can press the button the fastest.

ASSESSMENT PRE/POST-TEST

How can you use technology in an effective way to help the environment? ■ Can pupils produce programs including a range of instructions based on pressing the buttons or sensors? ■ Can pupils explain the instructions they used to produce each program?

OBJECTIVES

■ I can explain what the buttons and sensors on the micro:bit do ■ I can program sensors and buttons using the MakeCode editor ■ I can store data with variables using the MakeCode editor

CATCH/HOOK

Explain to pupils they will be using the micro:bit device, which is a special type of computer they can program. Provide pupils with a micro:bit and ask them if they can identify the following parts of the device, which they will be using during these lessons - LEDs, USB connector, Buttons, Accelerometer (Slide 3). Ask pupils to discuss whether the LEDs are inputs and outputs, and elicit that we say they are outputs, as they are displaying information from the computer. (Please note - the LEDs are also used as an input to detect light, although this is beyond the scope of this lesson.) Explain the buttons and accelerometer are inputs, as they take information from the outside world. Ask pupils to also identify other parts of the device and discuss their functionality using the guidance within the ‘Lesson overview’ as required. Explain to pupils they will be using the micro:bit to produce a button race game, which will enable them to see who can press the micro:bit buttons the fastest. Add that before we go on to make our game, pupils will ensure they can remember how to create a program using MakeCode. Show pupils MakeCode - https://makecode.microbit.org/ and ask them to share (Slide 4): ■ How to create a new project ■ How to place “show icon” blocks into the programming area ■ How to download the program ■ How to transfer the program file to the micro:bit Remind pupils of how to keep safe when using the micro:bit (Slide 5). Explain to pupils they are to create a program containing at least one image, which they should transfer to the micro:bit (Slide 6). Once pupils have finished the task, they should assist other pupils until everyone in the class has completed it successfully.

ACTIVITY INSTRUCTIONS

Using the buttons - 15 mins Explain to pupils the micro:bit’s buttons can be used to start different parts of our programs, or to make different things happen. Show pupils the image of the micro:bit and the various code blocks (Slide 7). Ask them to match up the different code blocks with the relevant button and sensor as follows: ■ on button A pressed - Button A ■ on button B pressed - Button B ■ on button A+B pressed - Buttons A and B ■ on shake - Accelerometer Demonstrate to pupils, using MakeCode, that the blocks related to buttons and sensors can be found in the “Input” section of the editor (Slide 8). Demonstrate to pupils how to produce a program using the ‘on button A pressed’ and ‘on shake’ blocks, such as displaying different images, as shown on slide 8. Emphasise that no image is displayed on the LEDs until the button is pressed or the device is shaken. Ask pupils to make and transfer a program to display different images for button A and when shaken, as shown on slide 9. Once complete, ask pupils to attempt the other tasks on the screen. Support pupils as required and remind them each new program needs to be transferred to the micro:bit if required. Introducing variables - 15 mins Explain to pupils we are now going to use the micro:bit to store data, such as to record how many times a button has been pressed (Slide 10). Explain that we can use a variable to store data within our programs. Using the whiteboard, explain to pupils you are going to demonstrate how a variable functions. Write the word ‘counterA’ at the top of the whiteboard and explain this is the name of the variable. Explain to pupils it is important we give the variable an appropriate name, as we need to be able to understand what it does and remember what it is storing. Show pupils the printed images of buttons A and B from the ‘UKS2 - Lesson 1 - Buttons’ file and explain they are going to see how the program on slide 11 functions. Ask one pupil to hold the image of button A and another pupil to hold button B. Explain to pupils you are now going to start the program and write ‘0’ on the whiteboard. Emphasise that you have ‘set’ the value of ‘counterA’ to zero, which is known as initialising the variable and it is important we do this at the start of our program to ensure we start from the correct value. Explain to pupils the ‘show number’ block is used to display the value of the variable, as it would not otherwise be shown. Ask a pupil to press the image of button A, then erase ‘0’ from the whiteboard and write ‘1’. Explain to pupils you have ‘changed’ the value of counterA by 1. Ask another pupil to press the image of button A, then erase ‘1’ from the whiteboard and write ‘2’. Explain you have again ‘changed’ counterA by 1. Repeat this process with 3-5 more pupils and change the number each time. Ask a pupil to press the image of button B, then erase the current value on the whiteboard and write ‘0’. Explain to pupils you have ‘set’ the value of the counterA variable to 0, rather than ‘changing’ it. Increase the value of counterA again using the button A image, then set it back to zero using the button B image. Check for pupil understanding using the following questions (slide 12): ■ Which blocks initialise the value of counterA? ■ Which blocks display the value of counterA on the LEDs? ■ Which block increases the value of counterA by 1? ■ Which block resets the value of counterA to 0? Ask pupils to make and transfer a program to change and display the value of the variable, as shown on slide 13. Once complete, ask pupils to attempt the other tasks on the screen. Support pupils as required and remind them each new program needs to be transferred to the micro:bit if required. Time for a race - 15 mins Explain to pupils that they are now going to create a program to see who can press a button the most times in 20 seconds. Show the algorithm on slide 14 and explain to pupils they should use the Code Creation sheet to match the required code blocks to each part of the algorithm. Working in pairs, ask pupils to complete the sheet. Once complete, as a class, ask pupils to share the blocks they might use for each part of the algorithm and produce the program on slide 15 on the board. An example program can be found here - https://makecode.microbit.org/_c7fKfy5zbPJ7 Ensure a range of pupils give suggestions as you make the program. (Note: This pedagogical approach, where all pupils work together as a class to produce a program, is known as ‘shared programming’.). Explain to pupils the order the ‘on button A pressed’, ‘on button B pressed’ and ‘on shake’ blocks are arranged is not important for the program to work, as the instructions are constantly checked whilst the program is running. Keeping the program produced as a class on the board, ask pupils to create their own button pressing game and to transfer it to the micro:bit. Using the timers, ask pupils to race their peers to see how many times they can press the button and who is the fastest. Emphasise to pupils they must both hold the device in two hands to ensure the micro:bit is not accidentally dropped. Explain to pupils that they can restart their program using the reset button on the back of the micro:bit if required.

Supplements

Any items in this section are the property & under the license of their respective owners.

REVIEW

Ask pupils to remind each other what a variable is used for in programming (Slide 16). Ask pupils to also share ways their racing game could be improved, such as including a timer within the program, messages or images during the game, or a rest button.

STANDARDS