Arduino and basic electronics

Complete the challenge

Wire up your Arduino and breadboard as shown in the diagram below. This is the same as in level 1.

Open up the Arduino sketch from level 1 and save it with the name C7-level2. It should look like this:

int ledPin = 5;
int buttonPin = 2;
int torchState = 0;

void setup() {
    pinMode(ledPin, OUTPUT);
    pinMode(buttonPin, INPUT_PULLUP);
}

void loop() {
    // State change code
    if (torchState == 0) {
        if (digitalRead(buttonPin) == LOW) { // If the button is pressed
            torchState = 1;                  // Change the torch state
            delay(200);                      // Wait for the button to stop bouncing
        }
    }

    if (torchState == 1) {
        if (digitalRead(buttonPin) == LOW) { // If the button is pressed
            torchState = 0;                  // Change the torch state
            delay(200);                      // Wait for the button to stop bouncing
        }
    }

    // LED control code
    if (torchState == 0) {
        digitalWrite(ledPin, LOW);
    }
    if (torchState == 1) {
        digitalWrite(ledPin, HIGH);
    }
}

Add a new section of code to change torchState from 1 to 2. You’ll need to duplicate and edit this:

    if (torchState == 0) {
        if (digitalRead(buttonPin) == LOW) { // If the button is pressed
            torchState = 1;                  // Change the torch state
            delay(200);                      // Wait for the button to stop bouncing
        }
    }

Also change the code that changes the torchState from 1 back to 0 - make it change from 2 to 0 instead.

Also add a new section of code to tell the Arduino what to do in torchState 2. You’ll need to duplicate and edit this:

    if (torchState == 1) {
        digitalWrite(ledPin, HIGH);
    }

Instead of using digitalWrite, use analogWrite.

The goal is to have the LED start off, then turn on, then go dim, then go off again, when you press the button each time.

Claim your achievement

I did it!

That’s fantastic!

Now claim your achievement.

Copy the saved sketch to your Year 8 Digital Tech folder on Google Drive.
Complete a claim slip. The code is C7 and the level is 2.

C7 — The torch

Level 2 — A 3-level torch

Complete the challenge

Claim your achievement