praktek penggunaan arduino dan sensor LDR | P5 rekayasa dan teknologi

Introduction

In this tutorial, we will learn how to use an Arduino Uno to control an LED based on readings from a Light Dependent Resistor (LDR). This project demonstrates the practical application of sensors and microcontrollers in electronics, making it ideal for beginners in engineering and technology.

Step 1: Gather Your Materials

Before starting, ensure you have the following materials ready:

• 1 Arduino Uno
• 1 smartphone with the Arduino Droid app installed
• 1 LED
• 2 resistors (220 ohm, 1/4 watt)
• 5 jumper wires
• 1 USB cable (to connect Arduino and smartphone)
• 1 OTG cable (if necessary)
• 1 breadboard (project board)

Step 2: Set Up the Circuit

Follow these steps to connect the components correctly:

1. Connect the LED:

   • Insert the LED into the breadboard.
   • Connect the longer leg (anode) of the LED to a digital pin on the Arduino (e.g., pin 8).
   • Connect the shorter leg (cathode) to one end of a 220-ohm resistor.
   • Connect the other end of the resistor to the ground (GND) on the Arduino.

2. Connect the LDR:

   • Place the LDR on the breadboard.
   • Connect one terminal of the LDR to the 5V pin on the Arduino.
   • Connect the other terminal of the LDR to an analog input pin on the Arduino (e.g., A0).
   • Connect a second 220-ohm resistor from the same terminal (connected to A0) to the ground (GND).

3. Verify Connections:

   • Double-check all connections to ensure they match the circuit diagram. A wrong connection can lead to incorrect readings or damage the components.

Step 3: Program the Arduino

Now we need to upload the code to the Arduino:

1. Download the Code:

   • Access the provided code using this link.

2. Upload the Code:

   • Open the Arduino IDE on your computer.
   • Copy and paste the downloaded code into the IDE.
   • Select the appropriate board type (Arduino Uno) and port.
   • Click on the upload button to transfer the code to your Arduino.

3. Review the Code:

   • Ensure that the code reads the LDR value and controls the LED based on the light intensity. The basic structure should include:

   int ledPin = 8;
   int ldrPin = A0;
   void setup() {
       pinMode(ledPin, OUTPUT);
   }
   void loop() {
       int ldrValue = analogRead(ldrPin);
       if (ldrValue < threshold) {
           digitalWrite(ledPin, HIGH);
       } else {
           digitalWrite(ledPin, LOW);
       }
       delay(100);
   }
   

Step 4: Test the Setup

1. Connect the Arduino to Your Smartphone:

   • Use the USB cable to connect your Arduino to your smartphone.
   • If using an OTG cable, connect the OTG to your smartphone, then plug in the Arduino.

2. Run the Application:

   • Open the Arduino Droid app on your smartphone.
   • Ensure it detects the Arduino connection.

3. Observe the LED Behavior:

   • Test the setup by covering and uncovering the LDR. The LED should turn on in low light and turn off in bright light.

Conclusion

You've successfully built a simple light-activated LED circuit using an Arduino Uno and an LDR. This project serves as a foundation for more complex Arduino applications involving sensors. For future projects, consider experimenting with different sensors or integrating more LEDs. Happy coding and experimenting!