2D: Nested Loops

Make sure that your CoDrone Mini is paired before starting the lesson! If you forgot how to do this, make sure to review how to pair to Blockly here.

Loops let you repeat sections of your code. They’re a great shortcut — without them, you might have to connect the same blocks over and over again, which can leave a lot of room for error.

There are three basic loops in Blockly:

• For loops will repeat the code inside them for the number of times you choose. 
• While loops will repeat the code inside them while a certain condition that you set is true.
• Until loops will repeat the code inside them until a certain condition that you set is true.

Nested loops are loops within another loop. You usually use nested loops when you need to repeat something that’s already within a loop.

How it works: when your program gets to the outer loop, it will go through the code in the nested loop until it’s complete. It will then move on to any other code in the outer loop. This process will repeat until all of the outer loop’s rounds are finished.

Let’s see how a nested loop works by programming one! Start out by writing a code for a square using a loop. We used a for loop, but you can use any type of loop you want for your program.

Next, drag another loop over to your workspace and put your square program inside of it. 

Don’t forget to add takeoff and land blocks before testing your program!

If you want to add more blocks to your outer loop but don’t want them to be in the nested loop, you can still do that! Drag the blocks you need to where you want them in your program. For example, with your last program, if you want your drone to pitch forward before flying in another square, you can add a flight direction block after your nested loop.

In geometry, a rotation is when a figure moves around one central point. Even as the figure turns, the size and shape will stay the same. 

To have your drone fly in a rotation with your square program, take out the flight direction block and replace it with a turn block. Next, have your drone turn left for 1 second at 50% power.

Challenge: Fly A Kite

You’ve probably seen a kite drawn like this:

You are going to program your drone to fly in a kite shape! Use a loop to program your drone to fly in a triangle, and then use nested loops to repeat that triangle 4 times in a rotation. Your final rotation does not have to look exactly like this kite, and know that your drone might drift a little. This is completely normal!