Variables are placeholders for numbers, letters and character strings. This means that a variable does not have to remain the same over the entire course of the program. This is especially useful if you want to use a certain information at different places in the program.

Variables can be defined using the ‘set item to’ block.

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In the drop-down menu of the block, you can rename the variable and create a new variable.


After a soccer game, you want to store in a variable how many goals were scored. This variable is then shown on the display

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In order to extend the simple example a little, it should now be possible to add points live. For every goal you score, you have to press the built-in button on the MCU once.

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Data types

Depending on what is stored in a variable you should define the correct data type. You define the data type with the help of the ‘as character’ block. This block is attached to a ‘set item to’ block. Afterwards the value to be stored is inserted in the free block section and the data type is selected in the drop down menu.

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In Blockly there are the following data types:

Characters: For single text characters

Text: For whole words or sentences

Boolean: For values that are either true or false (or 1 or 0)

Short number: for single digit numbers

Number: For whole numbers from -32,768 to 32,767

Large number: For large numbers from -2,147,483,648 to 2,147,483,647

Decimal: For decimal numbers



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