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Pseudocode

Our Program

  1. Create a new program
  2. In the variable section of our toolbox, click the ‘Make a Variable’ button. and call it ‘counter’

  3. Drag and drop the set block into the on start event, change the drop down to ‘counter’. It should look something like this:

    Step 01

  4. Drag and drop the on button A pressed event into our program.
  5. Add a change variable block into our event, associate it to the ‘counter’ variable we created and the ‘by’ value to 1
  6. Now display a ‘+’ sign, using the ‘show leds’ basic block.

  7. And finally a clear screen basic block.

    Step 02

  8. Great, we are half way there, now we need to write the B button event. We could start from scratch, but lets ‘duplicate’ the A button event, and change a few things. To duplicate it, right click on the A button event and select duplicate.
  9. Now you should have two, but one of them will be grayed out. Using the one that is currently grayed out, change the event to map to the B button, with the dropdown on the event.
  10. Additionally, change the plus sign in the show leds block to be a minus sign.

  11. Next change the change brick from a by value of ‘1’ to ‘-1’. When you are done you should have code that looks like this. Test it out in the simulator.

    Step 03

  12. Ok, now for our last requirement lets display the current value in counter when the micro:bit is shaken. Lets start by adding the on shake event.
  13. To that event lets display the value in counter using a show number basic block and the counter variable block.
  14. We now need to wait for one second and then clear the screen. To wait we use the pause basic block. It time is set in milliseconds, so for 1 second we need to set it to 1000.

  15. Now we can add the clear screen command. Our shake event should look something like this:

    Step 04

  16. Try our app out on the simulator, if everything looks good, lets name our app, save and download it to our micro:bit.