Display Constant Variable Value on Serial Monitor

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 determine how quickly an LED blinks 'Print' the value of the variable on the serial monitor. Notice how the computer swaps out the variable's name for its number value */ int wait = 1000; //variable named 'wait' that is an integer (whole number, no decimals), with a value of 1000 void setup(){ pinMode(2,OUTPUT); //LED Serial.begin(9600); //start the serial monitor } void loop(){ digitalWrite(2,HIGH); //turn on the LED delay(wait); //delay for 'wait' amount of time, 1000 milliseconds (1 second) Serial.println(wait); //'print' the value of the variable on the serial monitor digitalWrite(2,LOW); //turn off the LED delay(wait); //delay for 'wait' amount of time before restarting the loop } // (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!

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!

Add another line of code Serial.println(wait); after the second delay inside the void loop. Before you upload, what number do you think this second ‘Serial Print’ is going to display on the serial monitor?

Change the variable value up above the void setup where you created the variable. Upload and open the serial monitor to see the new value that is ‘printed’ there as the void loop runs. What happens if you make the variable value really small?

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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