How can you introduce students to the features of the BBC micro:bit (V2) and programming with just the micro:bit itself? The answer is this simple "WhenDo" application, which is the brainchild of David Whale.
Click here to open the WhenDo application in MakeCode.
Print out this handout for use in class.
The program allows you to specify an input event I and an output action O using just the A/B buttons of the micro:bit. Together, I and O make up a simple rule:
- When input event I occurs Do output action O
The micro:bit will execute this rule forever until you reset it, so you can create a new rule. Some events and actions use the micro:bit radio, in which case you get to specify the radio group to use. Then you can have multiple micro:bits (in a large group) work together!
First, press the A button to cycle through the following input events in the following order:
- A: press the A button
- B: press the B button
- S: shake the micro:bit
- F: hold screen face up
- U: hold screen face down
- D: see darkness (low light level)
- L: hear loud sound
- R: radio receive message
- E: press micro:bit emoticon
- P: press pin P0
When you find the input event you want, press the B button to accept it.
Each input event is displayed as an animation on the micro:bit screen, which are presented below (or via a single letter, as shown above, depending on how you configure the application):
Now, press the A button to cycle through the following output actions:
- A: all LEDs on
- H: show happy face
- G: show grumpy face
- R: radio send message
- P: play doorbell sound
- S: play slide sound
When you find the output action you want press the B button to accept it. The program will begin executing immediately, unless one of the input events or output actions is radio.
If you chose the radio receive input event or the radio send output action then you will also need to specify the radio group (channel) that will be used (1-16). This is especially useful if you are working in a large group with many micro:bits. Find your partner and agree on a radio group number. Write it on the whiteboard so everyone else knows that number is being used.
Press the A button to cycle through the channels (1-16). Press the B button to accept the current channel. Your program will now begin executing.
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