Variable LED Strip Pixels

Code

The code in the editor below is ready to run! Plug your Code Lab 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.


/* Use a variable to light the LED strip pixels one at a time */ #include "LEDStrip.h" //The LEDStrip.h library gives your code access to special functions exclusive to the LED Strip LEDStrip strip = LEDStrip(50, 13, 12); //Set up the strip by defining how many pixels (50) and which pins of the microchip are used (always 13 and 12 on Code Lab) int pixelCount = 0; //Create a variable called 'pixelCount' that is an integer (whole number) and starting value of 0 void setup() { } void loop() { strip.setPixel(pixelCount,200); //set the pixel that is equal to 'pixelCount' to a color value of 200 strip.draw(); //send the setPixel data to the strip pixelCount++; //increase pixelCount by one so the next delay(1000); //Wait 1000 milliseconds (1 second) before moving to the next pixel if(pixelCount==50){ //If the pixelCount variable reaches 15 (remember, pixels are numbered 0 - 49) pixelCount=0; //reset pixelCount to 0 so the LEDs start lighting up again strip.clear(); //turn off the pixels that are currently lit up } } // (c) 2021 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!

Video Notes for Code Lab Users:

  • You will use “50” instead of “15” as the first argument in your LEDStrip function.

  • The second and third arguments of the LEDStrip function (13 and 12) do not need to change. These connections are permanently set on Code Lab.

  • Your “if” statement will change so that pixelCount must equal 50 before pixelCount is reset to 0.

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 challenge? 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!

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?




2. Which syntax ends a single code command?