Introduction: LDR and IR Sensor

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Hi friend my name is Ankit singh probably this is my first Instructable hope you like this.

lets get started

As we already know IR sensor and LDR sensor which we have used several time in our projects well i have used plenty of times every time I noticed that most of the IR and LDR sensors uses LM358 and LM359 well this is a dual op-amp if you see the pin it clearly that it has 2 op-amp but commercial circuits used only one op-amp.That means we are not utilizing the full power of the op-amp and now a days we demand for fuels which is 100% combustible the same way we must expect max performance from our sensors too.

so today I will help make your own IR and LDR sensor which uses only one LM358 Op-amp ic and you use them anywhere you want well i used one for my college project.

Step 1: IR Sensor

What is IR sensor?

IR stands for Infrared rays it simply sends a continues beam of IR light which is not visible through human eyes but some animals can (but still we can see IR light with the help of cell phone camera) and the light gets reflected when falls on the objects the reflected light is received by a infrared receiver this signal is amplified by the op-amp which is used by the Arduino in this way we can find any obstacle in short range because of its wonderful property(can not reflect on black surface) its used for line following robot.

There are several circuits available online but you can use mine which is easy to understand.

Step 2: LDR Sensor

What is LDR?

LDR-Light dependent resistor

The resistance for the LDR changes with the change in the light the amount of light falls on it is inversely proportional to the resistance. for example when the room is dark the resistance is up to 2 Mega Ohms and when the room is bright then the resistance will be 5-6 Ohms.

with this type of sensor you can make Automatic light ON OFF system when it becomes dark the light turns ON and in the day time the light is turned OFF.

There are several circuits available online but you can use mine which is easy to understand.

Step 3: LDR+IR

As i already mentioned LM358 is a dual OP-Amp so we can make DIY LDR and IR together on a PCB. I have already made this on a general PCB you can visit youtube channel I will make it again on youtube.

Now i will continue with some of the breadboard model and schematic which will help you to make your own DIY LDR+IR module. it works extremely fine just make sure make you connections properly if you want to use power source greater than 5 volt i recommend you to use a 5 volt regulator.

Now its time to do a project assembling on a breadboard will take 10-30 minutes soldering on a perfboard will consume 1-3 hours it highly depends on your experience level. etching is a good option it will take 30-60 minutes. once your circuit is ready you can go to next step.

Step 4: Street Light Using LDR+IR Module

we can use this technique to built up an street light. there are already several types of street light projects out There. but whats different here we will use this LDR+IR module some street light uses IR and some street light turns on when and object passes(the car in most of the cases). And some other type uses LDR sensor alone and what happens is it turns ON when its dark and keeps glowing for the whole night sooo sad you know in most of the countries there save electricity and here we turn on the street light whole night this is were our IR+LDR module comes in play.

I think its enough for today in my next post I will make a street light using this IR+LDR module circuit.