Block Programming - Variables

Variables in block programming work similarly to those in text-based programming languages. They allow you to store and manipulate data in your program. Let's dive into their usage with an example:

Example: Distance Tracker

Imagine we have a robot that's capable of tracking the distance it has traveled. To do this, we'll need to create and use variables.

1. Creating a Variable: We start by creating a variable block named 'distance'. This variable will hold the total distance the robot has traveled.

2. Initializing the Variable: We'll set the initial value of 'distance' to 0 since the robot hasn't moved yet.

3. Updating the Variable: As our robot moves forward, we'll need to increment the value of 'distance' to reflect the new total distance traveled. For example, if our robot moves forward by 5 units, we'll add 5 to our 'distance' variable.

4. Displaying the Variable: We can use the 'distance' variable to display the total distance traveled on an LCD display connected to our robot.

The pseudocode for the blocks could look something like this:

# Create a variable 'distance'

distance = 0

# Inside a loop that controls the robot's movement:

repeat until program ends:

move_forward(5) # Move the robot forward 5 units

distance = distance + 5 # Add the distance moved to the total

display_on_LCD("Total Distance: ", distance) # Display the total distance

This program will continuously move the robot forward in increments of 5 units and update the 'distance' variable accordingly. It will then display the total distance traveled on an LCD screen.

Firstly, in your block programming interface, you'd look for a block that says Create variable... or something similar. This is where you'd enter the variable name, for our example it's 'distance'.

Next, you'll want to find a block that allows you to set or initialize the variable. For 'distance', we'd set it to 0 to start with.

Now, every time your robot moves, you'll want to update the value of 'distance'. In the block programming interface, this would look like finding a block that allows you to change the variable by a certain value. If your robot moves forward by 5 units each time, you'd use this block to add 5 to 'distance' every time the robot moves.

Lastly, you'll want to display the 'distance' variable. This will depend on your specific robot kit and block programming interface, but you'd generally look for a block that allows you to print or display a variable.

In a simplified sequence of blocks, it could look like this:

1. Create variable... > (input 'distance')

2. Set variable... > ('distance' to 0)

3. (In a loop) Move robot forward... > (by 5 units)

4. (In the same loop) Change variable... > ('distance' by 5)

5. (In the same loop) Display on LCD... > ('distance')