Interfacing Light Dependent Resistor LDR in Raspberry Pi

Learn interfacing Light Dependent Resistor LDR in Raspberry Pi. We will learn how LDR works. LDR is a type of resistor whose resistance varies according to surrounding light. Resistance will increase with the increase in light intensity. LDR also known as Photoresistor, are available in 5mm, 7mm, 10mm and many other sizes. So, let’s start.

Step 1: Required Components

LDR x 1
Breadboard x 1
Raspberry Pi x 1
1µf capacitor x 1
Jumper Wires

Step 2: Circuit Time

Make the circuit as per the given diagram. Connect one leg of LDR to VCC +5v. Now, connect long leg of the capacitor and another leg of LDR on the same track of breadboard. The ground short leg of the capacitor.

Circuit of Light Dependent Resistor (LDR) in Raspberry Pi

Step 3: Code Time

This is code for interfacing LDR in Raspberry Pi. First of all, we have to import LightSensor code for LDR form gpiozero library. Assign GPIO pin to variable ldr and also pass the GPIO pin number as an argument to LightSensor method. While loop print’s value of LDR.

Step 4: Run code to Raspberry Pi

Run the Python program in your Raspberry Pi after setting components as per circuit diagram. The LDR will give resistance to Raspberry Pi and Raspberry Pi. Screenshot of output is given as below.

Screenshot of Light Dependent Resistor LDR in Raspberry Pi

For running python code in Raspberry PI, visit:

4 thoughts on “Interfacing Light Dependent Resistor LDR in Raspberry Pi”

  1. It would be SUPER cool if you corrected the drawing, so the cap is correctly polarized. In the drawing, the cathode is connected to the ldr and the anode is connected to ground, and it should be the other way around, as the text explains.

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