6_1 Serial Monitor Toggle Variable

Serial Monitor Toggle Variable

Code

The code in the editor below is ready to run! Plug Code Lab Mini 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.

Restore 12 14 18 24 30

Monitor Upload Your Code!

/* Serial print the value of a variable that 'latches' on or off like the flashlight button */ int pressCount = 0; //An integer (whole number) variable to keep track of how many times the button is pressed void setup(){ Serial.begin(9600); //start the serial monitor to receive data pinMode(4,INPUT_PULLUP); //button } void loop(){ if(digitalRead(4)==LOW){ //if button 4 is pressed pressCount++; //++ is a way to add one to a variable. Now pressCount = its former value + 1 delay(250); //a delay allows you to release your finger from the button without counting multiple presses } Serial.println(pressCount); //'print' the value of pressCount if(pressCount > 1){ //if pressCount is greater than 1... pressCount = 0; //reset the count to 0 before the loop starts again } } // (c) 2023 Let's Start Coding. License: www.letsstartcoding.com/bsdlicense

 

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Compile errors:

Serial port monitor: Input: Send Close

 

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!

Change the delay inside the first ‘if’ statement to something small. Upload the code and open the monitor. Can you see the variable value change very quickly between 0, 1, and 2? The values will be streaming fast, so it might be hard to see! Hold down the button - what do you see now?

Change the value beside the ‘==’ sign in the second ‘if’ statement to something higher than 1. Now how does the variable change on the monitor? This is a sneak preview of the next chapter!