LDR Sensor with RPI | Light Sensor Raspberry pi Tutorial #6

Hey Friends, I’m here to discuss again an interesting and important article based on Raspberry Pi. Today we’re going to discuss Light Sensor Raspberry pi. The components for this project are very simple and are easily available in any market either online or offline. If you are starting coding with python or getting started with Raspberry Pi then make sure to visit my other Raspberry Pi articles to have a clear view of each function and module. So now without wasting any time let’s get started.



LDR Sensor is not another type of Resistor that reacts to the light nearby it. LDR is used in various projects which require tasks to be done based on the basis of the light in nearby surroundings. The construction is very simple for the LDR. To make an LDR a zigzag shape grove is over an insulating material(ceramic), inside this shape a photosensitive material like CdS, CdSe & PbS. These substances are reactive to light and upon getting exposed to light the photoelectric effect takes place.

The details phenomena are explained in my similar article on Pi PICO, which you can visit for more knowledge. The Light Sensor Raspberry pi is available in various shape sizes and colors of light-sensitive material depending on the range of resistance it can reach. For my convenience, I’m using the very basic one which reaches a range of 0KOhm to 1MOhm.

Material Required

LDR material required
  • Raspberry Pi (with keyboard, Mouse, and Display)
  • LDR Module
  • Breadboard
  • Jumper wires
S.NoComponent RequiredQuantityBuy Link
1.Raspberry pi 3B+1Amazon
2.Raspberry pi Cable1Amazon
3USB Mouse & Keyboard1Amazon
4.Raspberry pi Combo1Amazon
5.Jumper Wire40Amazon
7.Power supply1Amazon
9.220 Ohm Resistor1Amazon
10.LDR Sensor1Amazon

Light Sensor Raspberry pi Circuit Diagram

Light Sensor Raspberry pi circuit diagram

Raspberry PI

LDR Sensor

GPIO 11 Pin



+5 V, VCC



Raspberry PI


220-ohm Resistor

GPIO 13 Pin

Anode Terminal ( + )




Terminal 1


Cathode Terminal ( – )

Terminal 2

LDR Module OUT Pin to Board pin number 11 & LED to pin number 13 of Raspberry Pi according to BOARD numbering

Light Sensor Raspberry pi Code


At the beginning of the code, we’ve included or imported some basic modules which are required for the program to work efficiently. RPI & time modules are required for defining the pin and performing various functions on it and time for making time-related function work.

Further, we define pin mode to BOARD. You can set it to either BCM or BOARD according to your convenience. in this Light Sensor Raspberry pi I prefer board as it is easy to locate pins. Next, we define a while loop inside which we put our main code in the try and except method to make the code work until the Keyboard Interrupt arrives.


 import RPi.GPIO as gp  
 from time import sleep  
 while True:  
     if gp.input(11)==1:  
     elif gp.input(11)==0:  
   except KeyboardInterrupt:  

With this, we’ve completed our article on LDR RPI. If you come through any problem then ask me below, I’ll answer all of them.

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