Light Intensity Measurement Using Ldr And Arduino

Working of ldr controlled led using arduino.

Light intensity measurement using ldr and arduino.

Of course what s presented here is only the tip of the iceberg and these concepts could be applied to a wide variety of embedded systems. You can even use this as an emergency lighting system. Three powerful yet overlooked uses. In order to detect the intensity of light or darkness we use a sensor called an ldr light dependent resistor.

Overall i d say that the ldr light meter is good enough for a normal room when you just want a ballpark measurement of the lighting levels. Lx is the si unit of luminance measuring luminous flux per unit area. As the title says we are going to control the intensity of an led light emitting diode using an ldr light dependent resistor. The voltage divider output is feed to the analog pin of the arduino.

But more importantly we are going to look at how we take in an analog input make sense of that input and output what appears to be analog signal but it s not its actually pwm using an arduino board. On the right of. You can see a side by side comparison of the lx 102 light meter from lutron and our ldr light meter in the video below. The computation is an exercise in ohm s law v ir.

If you want to actually measure light intensity there are a number of ways to do so. Thakur definition the lux symbol. Use it to automatically turn a light on when there isn t sufficient light in a room. We need to compute r1 which will give us the light intensity in terms of v2.

We previously made many circuits using ldr which use ldr to automate the lights according to requirement. Unfortunately good light meter is not cheap. Normally in photography we use light meter. We have already seen the circuit to turn on an led during day and turn off the same at night using ldr and bc 547 here we will measure the light intensity around light sensor using an arduino mega.

I ll outline a couple options here in the context of arduino usage. It is difficult to measure in light in lux but possible to measure in some units although exactly lux. May 13 2016 arduino tutorials arduino intensity ldr light lux measurement meter manoj r. Circuit is simple and is done as shown in the following diagram.

As per the circuit diagram we have made a voltage divider circuit using ldr and 100k resistor. V2 is what the arduino senses.