USING AN LDR SENSOR WITH ARDUINO

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Hi Everyone, This is My First Arduino Tutorial Video. Today I'm Going to Show You How to Use a LDR or Light Dependent Resistor to Turn On and Off Another Circuit or LED. Wouldn't it Be Really Cool If Whenever a Room Gets Dark, a Light Bulb Automatically Turns ON and Eliminates the Darkness? In This Very Simple Project, I Am Focusing on Eliminating Darkness. You Can Even Use This as an Emergency Lighting System. Step 1: Principle ---------------- The LDR is a Special Type of Resistor Which Allows a Lower Voltage to Pass Through It (High Resistance) Whenever It's Dark and Higher Voltages to Pass (Low Resistance) Whenever There Is a High Intensity of Light. We Are Going to Use a 10k Resistor Along with the LDR to Create a Voltage Divider Circuit. The Varying Resistance of the LDR is Converted to a Varying Voltage That the Analog Pin of the Arduino Will Then Be Using in Its Logic. Step 2: Hardware Requirement ----------------------------- For This Very Simple DIY Arduino Project We Need: - A Breadboard - An Arduino Uno/Nano (Whatever Is Handy) - LED (Light Emitting Diode) - LDR (Photoresistor) - A 10K Resistor for Creating the Voltage Divider and a 220ohm Resistor for the LED - Few Breadboard Friendly Connecting Wires - And a USB Cable to Upload the Code to the Arduino Step 3: Assembly ------- To Assemble the Circuit, Follow These Steps: - Connect the 3.3v Output of the Arduino to the Positive Rail of the Breadboard - Connect the Ground to the Negative Rail of the Breadboard - Place the LDR on the Breadboard - Attach the 10K Resistor to One of the Legs of the LDR - Connect the A0 Pin of the Arduino to the Same Column Where the LDR and Resistor Is Connected (Since the LDR Gives Out an Analog Voltage, It Is Connected to the Analog Input Pin on the Arduino) - Now Connect the Other End of the 10K Resistor to the Negative Rail - And the Second (Free) Leg of the LDR to the Positive Rail Step 4: The Code ------ Here is the Code for This Project: ```c const int ledPin = 13; const int ldrPin = A0; void setup() { Serial.begin(9600); pinMode(ledPin, OUTPUT); pinMode(ldrPin, INPUT); } void loop() { int ldrStatus = analogRead(ldrPin); if (ldrStatus <= 200) { digitalWrite(ledPin, HIGH); Serial.print("It's Dark, Turn on the LED: "); Serial.println(ldrStatus); } else { digitalWrite(ledPin, LOW); Serial.print("It's Bright, Turn off the LED: "); Serial.println(ldrStatus); } } ``` Thanks Again for Watching This Video! I Hope It Helps You. If You Want to Support Me, You Can Subscribe to My Channel and Watch My Other Videos. Thanks, See You in My Next Instructable!