Turn Knob Sets 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.

/* Use the turn knob to control the brightness of an LED */ void setup() { pinMode(A2,INPUT); //turn knob in the smaller block of ports with the + and - ports pinMode(6,OUTPUT); //LED } void loop() { int brightness = analogRead(A2)/4 ; //Create a variable called 'brightness' that is an integer (whole number) //The brightness variable value takes the reading from the turn knob and divides it by 4, so it has a range of 0 to 255 //analogWrite works on ports 3,5,6,9,10,11 and has a range of 0-255 analogWrite(6,brightness); //set the LED's brightness equal to the value of the 'brightness' 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 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 more LEDs to this program that fade up and down with the turn knob. Remember that only ports 3,5,6,9,10, and 11 can fade an LED.

Add in a delay(500); after the line of code with analogWrite(6,brightness);. Try to predict how this will change the program before you upload it.

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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