2.7: Functions

Make sure that your drone is connected with Blockly before starting the lesson! If you are unsure of how to connect, go back to lesson 1.1 to review!

Functions are a way to save time and energy by storing commonly used blocks of code in one named set. For a real-world example, when you’re drinking a glass of water, the entire task might look like this:

1. Find glass
2. Bring over to water source
3. Pour water into glass
4. Make sure water doesn’t overflow!
5. Drink water

But instead of saying all of that, you could just say you’re drinking water! Functions work the same way. Multiple lines of code can be included in one function that you name and set up to be used in your program.

To define a function, or explain what is going to be in it, you will need the to do something block in the pink functions menu. Drag that to your workspace and then name your function in the white box. This should be something memorable that describes your function well. Next, drag the blocks you need into the function.

Try it now! Make a function that has the name “pushup” and that has your CoDrone EDU do a pushup. It should take off, hover, and land.

Once you define a function, you should see a block for it in the functions menu. To use it, drag it into your workspace and drop it to wherever you would like to see it in your program.

Remember your very first challenge with CoDrone EDU? You needed to see how many drone pushups you could do. Try doing this now with a loop and your new function!

To use a function in your flight program, drag its function block to where you would like to see it in your code.

Try this out now! After your CoDrone EDU does a few drone pushups, have it take off, pitch forward at 100% power for 1 second, and then land.

If you plan on using your function later on, do not remove it from your workspace! Doing this will delete the entire function and you will not be able to locate it in the functions menu. The image on the left shows the function appearing in the menu. The image on the right shows the function disappearing from the menu if the workspace is cleared.

Challenge: Initialize

Write functions so that CoDrone EDU can fly in your name’s initials! Start with the initial for your first name and the initial for your last name, and then use them in a flight program. To simplify the letters, try “writing” the letters in block-style with straight lines instead of curved paths.

In this lesson, you learned how to write more efficient code by grouping commands into functions. Functions are defined and then can be used in your program!