LED Pixel Light Meter

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.


/* Use the light sensor to control the number of pixels lit on Buzz's wingspan */ #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() { pinMode(A1,INPUT); //light sensor } void loop() { int pixelCount = analogRead(A1); //create a variable named pixelCount that is an integer and checks the reading A1 pixelCount = map(pixelCount,0,1023,15,0); //'map' the readings from A1 onto Buzz's pixels //Now a reading of 0 on the light sensor = 15 on the LED strip. A light reading of 1023 = 0. A reading of 512 = 7 or 8 wings.clear(); //clear the strip before you start showing the pixels on it /* Create a variable i that has a starting value of 0 and, as long as i is less than pixelCount, run the code between the curly braces, then increase the value of the 'i' variable by 1*/ for(int i = 0; i < pixelCount; i++){ wings.setPixel(i,200); //Use the variable 'i' to set which LED pixel is being lit up } wings.draw(); //send the setPixel data to the LED strip } // (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!

This graphic shows how some of the values from the light sensor will 'map' onto the number of LED pixels, except that Buzz has a pixel range of 0 to 15, not 0 to 14.

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!

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?