7_20 Turn Knob Sets Pixel Color

Turn Knob Sets Pixel Color

Code

The code in the editor below is ready to run! Plug Code Lab Mini in to your computer's USB port, make sure that your Code Lab Mini Rainbow Add-On (sold separately) is attached, 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.

If you haven't set up your Code Lab Mini Rainbow Add-On yet, visit Chapter 0 to watch a video showing you how to do that.


/* Use the turn knob to control the color of the LED rainbow */ #include "LEDStrip.h" //The LEDStrip.h library gives your code access to special functions exclusive to the LED Pixels LEDStrip rainbow = LEDStrip(15, 13, A5); //Set up the pixels by defining how many pixels (15) and where it's connected to Code Lab Mini (always 13 and A5) void setup() { pinMode(A0,INPUT); //turn knob } void loop() { int color = analogRead(A0); //Create a variable color that is an integer (whole number) and uses the analogRead of A0 as its starting value color = map(color,0,1023,0,299); //Because analogRead has a range of 0-1024 and the color range is only 0-299, use 'map' //map matches up two ranges of values. Now, a 1023 analogReading equals color 299. A 0 reading equals 0. A 512 reading equals about 150 rainbow.setPixel(rainbow.ALL,color); //set all pixels to a color value equal to the variable rainbow.draw(); //send the setPixel data to the rainbow } // (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!

LED Pixel Color Spectrum


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


Graphic of the Map Function

This graphic represents how some values from the turn knob will be 'mapped' onto the pixel colors of the LED pixels.


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!