IR Obstacle Sensor Without Using Arduino or Any Microcontroller

Introduction: IR Obstacle Sensor Without Using Arduino or Any Microcontroller

In this project we are going to make a simple obstacle sensor without using any microcontroller

Step 1: About This Project

In this project we are going to make a Obstacle sensor without the Help of any Microcontroller. Obstacle sensor have many uses . since we are not using any microcontroller , so this project is cheaper also.

Most importantly we can extend this project to Fire alarm system etc. Only thing we have to do is to change the sensor.

Step 2: To Make This Project ,We Should Have Following Components


2. IR sensor(1*1)

3. NPN transistor(1*1)

4. Resistor(300ohm,10k ohm)

5. Buzzer(1*1)

6. Led(1*1)

7. 9v DC battery

8. Jumper wires

Step 3: Working of IR Sensor

In IR sensor there are three pins, Vcc, Gnd and Out.

Out pin sends logic high(+5V) when IR detects any Obstacle and It sends Logic Low(0V) when does not Detect any Obstacle.

To use IR sensor we connect Vcc of sensor to Positive terminal of battery , and Gnd pin of sensor to negative terminal or ground of the battery.

Step 4: Circuit Configuration

Step1 : Connect positive terminal of battery to Positive Rail of BreadBoard and Negative terminal of battery to negative rail of breadboard. Positive and negative rail are the topmost and bottommost row of Breadboard.

Step-2 : Take the NPN transistor and place it on the breadboard. take a look at transistor and note which pin is base, emitter and collector pin.

Step-3: connect emiiter of transistor to ground or negative rail of breadboard where negative terminal of battery is connected.

step-4:Connect Vcc pin of IR sensor to positive Rail ,Gnd pin to negative rail of breadboard.Connect Out pin of Sensor to base of the Transistor but in between base and Out pin of sensor connect resistance of value 10K.for this one end of resistance is connected to Base of transistor and second end of resistor is connected to OUT pin of sensor.

Step-5: Take a led , Take 330ohm(330-10000hm) resistor.Connect led's ANODE pin to one end of resistor. Connect Second end of Resistor to Positive Rail of Breadboard. and cathode pin of Led to collector of transistor.

similarly Connect positive side of Buzzer to positive rail of breadboard,and negative side to collector of breadboard.

Step 5: Connection Diagram

Note: In the Diagram shown we connected positive pin of battery to vcc of sensor and Gnd pin of sensor to negative pin of battery , and we connected collector of transistor to Vcc separately . But On the breadboard connect all positive pin to positive rail of breadboard and negative or ground pin to negative rail battery so that we have to use only one battery.

i have connected emmiter with resistor . you can skip this step connect directly ground to emitter.

Step 6:

This is my first post. so please comment guys and send your feedbacks.

1 Person Made This Project!


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3 years ago

why have we used the 10k ohm and 300k ohm resistor?


Question 4 years ago

Can I make this project with just a receiver and no emitter? I have a receiver and a remote controller and I wanted to make the senor run a motor without using an Arduino or programmable component.


Question 4 years ago on Introduction

I followed all the steps.
But the LED and buzzer are always On when there is no obstacle. They switch off when it sees an obstacle. So it is the opposite of what is expected. How do I fix this ?I need the buzzer to be on when there is an obstacle.


5 years ago

Thanks for sharing :)