How to Use a Photoresistor (Light Sensor) with Arduino (Lesson #27)

The video tutorial explains how to use a photoresistor as a light sensor in Arduino projects. It covers the basic principles of how photoresistors work, including their resistance changes with light levels. The tutorial guides viewers through building a circuit using a voltage divider and connecting it to an Arduino. It also explains the code needed to read sensor values and control an LED based on light levels. The video includes a simulation demonstration and discusses how to adjust resistor values for different applications.

What is a common application of photoresistors in everyday devices?

• Detecting motion

• Measuring temperature

• Detecting sound levels

• Measuring ambient light levels

How does the resistance of a photoresistor change with light levels?

• Increases with more light

• Fluctuates randomly

• Decreases with more light

• Remains constant

Why can't an Arduino measure resistance directly?

• It can only measure voltage

• It can only measure light

• It can only measure current

• It can only measure temperature

What is the purpose of a voltage divider circuit in this context?

• To measure current changes

• To measure voltage changes as a proxy for light levels

• To decrease the voltage

• To increase the resistance

What command is used to read the sensor value in Arduino code?

• digitalWrite

• digitalRead

• analogWrite

• analogRead

What happens when the sensor reading is below the threshold in the code?

• The LED turns off

• The LED turns on

• The LED changes color

• The LED blinks

How can you adjust when the sensor triggers in the Arduino setup?

• By changing the LED color

• By using a different sensor

• By adjusting the resistor value and threshold in the code

• By changing the Arduino model