Buttons Raise and Lower LED Light Brightness

Use the ‘Parts List’ image along with the component cards in your box to correctly plug in the electronic hardware to your Maker Board. The colorful dots next to the legs of the components match up to the ports where that leg should go on Maker Board’s ports.

Code

The code in the editor below is ready to run! Plug in the electronic components just like the Parts List card above, connect Maker Board to your computer's USB port with the cable, and hit 'Upload Your Code!'. Tinker with the code and change something! If you get stuck, you can hit the 'Restore' button to make the code go back to the working example.


/* Pressing one button raises the brightness of and LED, pressing another button lowers the brightness */ int brightness = 0; //create a variable named 'brightness' that is an integer (whole number) and starting value of 0 void setup(){ pinMode(11,OUTPUT); //LED. analogWrite() function works on ports 3,5,6,9,10,11 and lets you send values from 0 to 255 pinMode(2,INPUT_PULLUP); //button 1 (raises brightness) pinMode(6,INPUT_PULLUP); //button 2 (lowers brightness) } void loop(){ analogWrite(11,brightness); //use the brightness variable to determine how bright the LED is (0-255) if(digitalRead(2)==LOW){ //If the button on port 2 is pressed brightness++; //increase brightness variable by 1 delay(20); //a delay means you can see the fade. Without it, the light value jumps too quickly } if(digitalRead(6)==LOW){ //If button on port 6 is pressed brightness--; //lower the brightness on the LED delay(20); //delay allows you to see the fade. // -- is shorthand for 'subtract one from the variable' } } // (c) 2019 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!

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?