Lesson 4 · Inputs with Variables

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Suggested Time: 60-75 minutes

Lesson Plan

Review

• Previous week
• Critical thinking based on previous question

Step 1: Getting The Input Value Into A Variable (15 minutes)

A variable is like a bucket that stores information. A variable has a name, which is the name of the bucket, and it also has a value, which is the stuff that is inside the bucket.

The program below creates a variable named “button”, and it sets it the value “1” if the button is pushed, and “0” if the button is not pushed.

Study the program below to make sure that you understand how it works.

int button = 0 ;

void setup()
{
  pinMode( 2 , INPUT);
  pinMode( 7 , OUTPUT);
}

void loop()
{
  if (digitalRead(2) == HIGH)
  {
    digitalWrite( 7 , LOW );
    button = 0;
  }
  else
  {
    digitalWrite( 7 , HIGH );
    button = 1;
  }
}

Step 2: Displaying The Variable On The Serial Monitor (45 minutes)

Now we will display our variable to the screen. We do this by using serial println.

int button = 0 ;

void setup()
{
  pinMode( 2 , INPUT);
  pinMode( 7 , OUTPUT);
  Serial.begin(9600);  
}

void loop()
{
  if (digitalRead(2) == HIGH)
  {
    digitalWrite( 7 , LOW );
    button = 0;
  }
  else
  {
    digitalWrite( 7 , HIGH );
    button = 1;
  }
  Serial.print("The button is: ");
  Serial.print(button);
  Serial.println();
  delay(500);
}

Once you upload the code, click on “Serial Monitor” to see your data displayed!

Step 3: Customizing Your Message

Modify the message so that it says “the button status is: _____”.

Variables and Serial Monitor

Challenges

Now that you know how to store input values and display them, try the following challenges!

• Display your robot’s name on the screen
• Display on the screen whether the light is on or off. Display “YES” for on and “NO” for off. If programmed correctly, the message should change whenever you push the button.
• Advanced Create a program so that your Arduino can display the total number of times the button has been pressed. It should keep counting higher each time you press the button.

Student had idea to add light sensor, photo sensor and sound sensor. The buzzer can be modified to be used as a sound sensor

REFLECTION

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Comprehension

• What are we assessing?

Challenges

• What was hard in today's class?

Enjoyment

• What was fun about today's class?

Mindset

• What did you learn about yourself?
• What would you like to improve?

Community

• How can what you learned impact those around you?

Additional Resources