Introduction: DIY IR Proximity Sensor
In this post I will show how to make a simple IR proximity sensor
IR Proximity have one IR LED & one Photodiode
LM358 IC is used in this project
Basically IR LED will transmitte Infrared light when this light fall on reflecting surface (white surface) it will fall back on Photodiode so in proportion of IR light fall on Photodiode the internal resistance of photodiode change
LM358 get input from this photodiode and gives output
To complete this project I ordered Electronics components from WWW.LCSC.COM
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Step 1: VIDEO
Step 2: Component Required
1] IR LED :- https://lcsc.com/product-detail/Infrared-IR-LEDs_...
2] PHOTODIODE :- https://lcsc.com/product-detail/Infrared-Receiver...
3] LM358 IC :- https://lcsc.com/product-detail/General-Purpose-Am...
5] Resistors :- https://lcsc.com/products/Resistors_308.html
6] Potentiometer :- https://lcsc.com/product-detail/Precision-Potenti...
7] Battery Holder :- https://lcsc.com/product-detail/Battery-Holders-C...
Step 3: CIRCUIT DRAWING
To figure out which terminal is anode and which terminal is cathode
The LED diode bigger leg is Anode(+) and shorter leg is cathode(-)
IR LED anode is connected with 5V DC and cathode is connected with 200 ohm resistor and GND is connected to the other end of resistor
Cathode of Photodiode is connected with 5V DC and Anode is connected with PIN 3 of LM358 IC & 10K OHm resistor, GND is connected the other end of resistor
50K OHM potentiometer two adjecent legs connected with 5V & GND and middle led is connected with PIN 2 of LM358 IC
5V connected with PIN 8 of LM358 IC
GND is connected with PIN 4 LM358 IC
A output load (LED) is connected with PIN 1 with 330 OHM resistor in series.
So IR LED will transmitte Infrared light when this light fall on reflecting surface (white surface) it will fall back on Photodiode so in proportion of IR light fall on Photodiode the internal resistance of photodiode change
LM358 get input from this photodiode at PIN 3 and compare with threshold signal coming from potentiometer at PIN 2 and glow the LED
Potentiometer is used to adjust the sensing range of sensor