In this project we will monitor the room temperature using a LDR_NSL19_M51 light dependant resistor (LDR) and 4Duino. The resistance of the LDR varies significantly with ambient light hence it can detect surrounding light intensity changes in real time. In this project 4Duino’s resistive touch display is used as a means for displaying the detected light intensity using LED digits and an angular meter.

HOW IT WORKS

Project 9 - LDR Sensor

COMPONENTS

  • 4Duino
  • LDR sensor
  • Bread Board
  • Jumper cables
  • µSD card
  • Micro USB cable

IMPLEMENTATION

Step 1: Build

Build the circuit as shown in the following diagram and schematic.

LDR-Sensor-Build

Step 2: Program

Workshop 4 – 4Duino Extended Graphics environment is used to program this project.

This project requires the Arduino IDE to be installed as Workshop calls the Arduino IDE for compiling the Arduino sketches. The Arduino IDE however is not required to be opened or modified to program the 4Duino.

LDR-Sensor-program

Open this file using Workshop 4.

Note: Download the project here.

Step3: Comms Port

Connect the 4Duino to the PC using µUSB cable.

Then navigate to the Comms tab and select the Comms port to which the 4Duino connected.

Led-control-4

Step4: Compile and Upload

Finally, go back to “Home” tab and now click on the “Comp’nLoad” button.

Led-control-5

The Workshop 4 IDE will prompt you to insert a µSD card to the PC in order to save the widget images. Insert µSD card, select the appropriate drive and press button “OK”.

LDR-Sensor-compile

If the µSD card has the widget images you can click button “No Thanks”.

Step 5: Insert µSD card

After uploading the program in to the 4Duino, it will try to mount the µSD card. If the µSD card is not present it will prints an error message.

LDR-Sensor-Insert

All you need to do is insert the µSD card you saved the image files into the 4Duino.

DEMONSTRATION

Now you can read the light intensity displayed on 4Duino.

LDR-Sensor-demonstration1

LDR-Sensor-demonstration2