Blinking LEDs - Escape the Apocalypse

What is an LED?

• A type of rechargeable battery.

• A device that emits light when electricity passes through it.

• A special type of screen used in televisions.

• A digital sensor for capturing images.

What does the acronym LED stand for?

• Luminous Electric Device
• Low Energy Display
• Laser Emitting Detector
• Light Emitting Diode

Arrange the following steps in the correct order to describe how an LED works.

• Electricity flows through the LED.

• Electrons move and bump into each other, creating energy.

• The LED is correctly connected to the circuit.

• The LED emits light.

Matching Question: Match the following milliseconds to their equivalent in seconds.

Groups:

(a) 1000 milliseconds

,

(b) 500 milliseconds

,

(c) 250 milliseconds

,

(d) 2000 milliseconds

• 0.25 seconds

• 2 seconds

• 1.00 second

• 0.50 seconds

Can you name three everyday products, not discussed in the lesson, that use LEDs?

Match the terms with their correct definitions.

• digitalWrite()

• Core of Arduino programs; runs repeatedly after setup() and executes main tasks.

• delay()

• Executes once when you reset or power on the Arduino board; initializes the digital pin LED_BUILTIN as an output
• void loop()

• Used to control digital pins; sets pin voltage to HIGH or LOW.

• void setup()

• Used to introduce pauses in Arduino programs; pauses program execution for a specified time

Fill in the Blank: digitalWrite(LED_BUILTIN, ​ (a)   ); turns the built-in LED ON. digitalWrite(LED_BUILTIN, ​ (b)   ); turns the built-in LED OFF.

• LOW
• HIGH
• OFF
• ON

n the command delay(1000);, the number 1000 represents a time delay in what unit?

• Seconds

• Milliseconds

• Minutes

• Microseconds

Put the following code lines in the correct order to make an LED blink on an Arduino.

•   digitalWrite(LED_BUILTIN, HIGH);  // turn the LED on (HIGH is the voltage level)

    delay(1000);                      // wait for a second

•   digitalWrite(LED_BUILTIN, LOW);   // turn the LED off by making the voltage LOW

    delay(1000);                      // wait for a second

• void setup() {

    // initialize digital pin LED_BUILTIN as an output.

    pinMode(LED_BUILTIN, OUTPUT);

  }

• // the loop function runs over and over again forever

  void loop() {

How would you modify the code to make the LED signal more attention-grabbing?