Arduino and basic electronics

Complete the challenge

Your challenge is to turn the LED off when button D7 is pressed, and turn it on when button D7 is not pressed.

Start with the sketch from level 2. It should look like this:

Save your Arduino sketch. Name it C4-level3.

int inputPin = 7;
int ledPin = 10;

void setup() {
    pinMode(ledPin, OUTPUT);         // set up pin "ledPin" as an output.
    pinMode(inputPin, INPUT_PULLUP); // set up pin "inputPin" as an input.
}

void loop() {
    if (digitalRead(inputPin) == HIGH) {  // check if the button is pressed
        digitalWrite(ledPin, HIGH);    // turn the LED on
    } else {
        digitalWrite(ledPin, LOW);     // turn the LED off
    }
}

Remember, your challenge is to turn the LED off when button D7 is pressed, and turn it on when button D7 is not pressed.

I can give you a hint if you need it, but have a go by yourself first.

You have 2 options. Either change something in the line that that says

    if (digitalRead(inputPin) == HIGH) {  // check if the button is pressed

or change something in the lines that say

        digitalWrite(ledPin, HIGH);    // turn the LED on
    } else {
        digitalWrite(ledPin, LOW);     // turn the LED off

Make your code do the opposite of what it does now - change LOW to HIGH and change HIGH to LOW.

You have 2 options. Either change the if line to this

    if (digitalRead(inputPin) == LOW) {  // check if the button is not pressed

or change the digitalWrite lines to

        digitalWrite(ledPin, LOW);    // turn the LED off
    } else {
        digitalWrite(ledPin, HIGH);     // turn the LED on

C4 — Digital inputs

Level 3 — The Backwards Light

Complete the challenge

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