LED Pixel Rainbow

Code

The code in the editor below is ready to run! Plug Buzz in to your computer's USB port with the cable and hit 'Upload Your Code!' to see what it does. Change something in the code, like a delay or pin number. Try to add something new to the program - it's yours to tinker with! You can always press the 'Restore' button to return the code to the working example.

// Turn on each pixel of Buzz's LED pixels in sequence, changing the color of each pixel #include "LEDStrip.h" //The LEDStrip.h library gives your code access to special functions exclusive to the LED Pixels LEDStrip wings = LEDStrip(16, A4, A5); //Set up the pixels by defining how many pixels (16) and where it's connected to Buzz (always A4 and A5) void setup() {} void loop() { /* Create a variable i that has a starting value of 0 and, as long as i is less than 16, run the code between the curly braces, then increase the value of the 'i' variable by 1*/ for(int i = 0; i < 16; i++){ wings.setPixel(i,i*18); //Use the variable 'i' to set which LED pixel is being lit up //use the i variable times 18 (i*18) to set the color value. wings.draw(); //send the setPixel data to the LED strip delay(100); //delay 100 milliseconds (0.1 second) before running the 'for' loop again } wings.clear(); //clear off all the pixels wings.draw(); } // (c) 2023 Let's Start Coding. License: www.letsstartcoding.com/bsdlicense

Walkthrough Video

Watch the video for a line-by-line explanation of how the example program works. Then you'll be ready to make some changes of your own!

Buzz’s LED Pixel Color Spectrum

Use this spectrum to estimate the color values you'll need for your 'setPixel' arguments to achieve your favorite color!

Challenges

Can you complete the challenges? Change the code in your code editor above. Upload your code to see the effect when you're finished. Complete a challenge? Check it off the list!

Add this line of code after the closing curly brace ( } ) of the ‘for’ loop :
wings.clear();
How does that change how the program runs?

Change the delay in the code. This change will be more obvious if you leave the wings.clear(); code in the program from the first challenge.

Change the second argument of the setPixel function from i*18 to a different multiple like i*5. How does this change the colors you see?

Concepts

These are the new code concepts covered in this example program. To become a great coder, read through these concepts to learn new vocabulary.

Quiz

If you're having trouble, try to run an experimental program or look at the example code to help you find the answer.

1. Which syntax ends the entire 'void loop' function?

semicolon ;
parentheses )
closing curly brace }

2. Which syntax ends a single code command?

semicolon ;
closing curly brace }
period .

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