Light Intensity Measurement Using Ldr And Arduino

Working of ldr controlled led using arduino.

Light intensity measurement using ldr and arduino.

V2 is what the arduino senses. If you want to actually measure light intensity there are a number of ways to do so. In order to detect the intensity of light or darkness we use a sensor called an ldr light dependent resistor. We need to compute r1 which will give us the light intensity in terms of v2.

Lx is the si unit of luminance measuring luminous flux per unit area. That possibly able to deliver an idea about intensity of light. We previously made many circuits using ldr which use ldr to automate the lights according to requirement. Unfortunately good light meter is not cheap.

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. Normally in photography we use light meter. On the right of. Circuit is simple and is done as shown in the following diagram.

You can even use this as an emergency lighting system. Thakur definition the lux symbol. The ldr is a special type of. Three powerful yet overlooked uses.

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. 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. The computation is an exercise in ohm s law v ir. I ll outline a couple options here in the context of arduino usage.

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. As per the circuit diagram we have made a voltage divider circuit using ldr and 100k resistor. Use it to automatically turn a light on when there isn t sufficient light in a room. The voltage divider output is feed to the analog pin of the arduino.

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.