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micro:bit Multitasking with MakeCode

2023-04-13 | By Kitronik Maker

License: See Original Project micro:bit

Courtesy of Kitronik

Guide by Kitronik Maker

In this blog we are going to look at how we can multitask on the BBC micro:bit with ‎MakeCode. In our example we used the Kitronik HaloHD to visually indicate the ‎micro:bit running two different tasks at the same time. We show the micro:bit ‎multitasking by having the HaloHD light up in two separate pulses, going in ‎opposite directions at different times.‎

 halo_1

Below is the embedded MakeCode project we used for the HaloHD example. Next, ‎we’ll step through how the multitasking parts of this project piece together.‎

code_2

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Inside the on start block we want to setup a flag variable called runA which we’ll ‎set to false. The runA variable is used to tell the micro:bit when to start executing ‎our two tasks.‎‎ ‎

task_3

Next, we setup the on button A pressed block to trigger our tasks to run by ‎setting runA to true.‎

task_4

Then, we have our two forever loops which are used to run our two tasks. In ‎each forever loop our task sits inside of an if runA then block. This means that ‎when the runA variable is set to true the code inside the block will be executed. In ‎the first task, we have the micro:bit pause for 1 second before it starts running the ‎code in this task. In the second task, we have the micro:bit pause for 2.5 seconds ‎before it starts running the code in this task. The different delays between the two ‎tasks can be seen in the example as the blue side of the HaloHD begins to fill after ‎the red side is already half full.‎

loops_5‎ ‎

To allow for proper multitasking on the micro:bit, it is important that there are some ‎delays inside of the task. This is done in the example by having the ‎tasks pause for 50 to 100 milliseconds in between updating an LED. By having ‎a pause block inside the task, we allow the micro:bit to swap over to the other task ‎temporarily and continue executing the code inside of there.‎

Finally, at the end of each task we want to set the runA variable to false, to stop the ‎tasks from being run again the next time the forever loop repeats itself.‎

variable_6

‎©Kitronik Ltd – You may print this page & link to it but must not copy the page or part thereof ‎without Kitronik's prior written consent.‎

制造商零件编号 2012414
MICRO:BIT V2 SBC-BOARD ONLY
OKdo
制造商零件编号 5672
KITRONIK ZIP HALO HD FOR MICRO:B
Kitronik Ltd.
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