Want An Analog Light Detector That Will Output 0 to 5 VDC depending on Light Intensity

[jeangv]

I have a HomeSeer system that I want to be able to detect light intensity. I am considering using the HomeSeer ADIO-100 Analog / Digital System Interface that has 8 analog inputs.

I need to find (or build if needed) a light sensor that will output 0 VDC - 5 VDC depending on the intensity of the light. Does anyone have any ideas? I want to be able to use this light sensor both indoors and outdoors and it will be connected over 100 feet of CAT 5e.

Thanks for any help,
Jean-Marie Vaneskahian
[email protected]

 

[BraveSirRobbin]

Your accuracy would determine the methodology needed. What do you want this for? A simple sensor to dim lights (i.e. fairly accurate) or a sensor measuring the potential input of sun/outdoor light to calculate a solar panel's potential output (watts per centimeter squared)?

Methods could range from a simple CdS photocell purchased at Radio Shack to a photodiode/photomultiplier calibrated sensor system.

I'm guessing you just need a quick and dirty ambient light sensor to set the dim level of lighting. If that's the case, I could just apply some DC bias across one of those Rat Shack sensors (they all have different resistance varying ranges/active area sizes) and see what works out for you.

Here is a decent example of how to do this. I used these sensors to detect when an appliance's light was on/off here with success.

 

[jeangv]

BraveSirRobbin, that was an EXCELLENT response!!! The article you pointed me to that explained how Photocell worked was great.
My planned use is for outdoor sunlight detection to trigger outdoor lighting dim levels. I was to place the sensor on the south facing side of the roof of the house.

Are there any weatherproof sensors out there that will generate an analog output? If I had to build my own, are there any weatherproof enclosures that have a window for the photocell?

Thanks so much for the help and educating me.

Jean-Marie Vaneskahian
[email protected]

 

[chedemefedeme]

Not sure if this will work with your board, but I did the following:

1) Buy variety pack of photoresistors for a few bucks at radio shack
2) Connect a random one directly to a zone on my elk
3) Write custom rules in the Elk that monitors the zone voltage

It works PERFECTLY. I have one in a west window of my house (so tiny nobody ever sees it there) that automatically closes the shades on the west facing side of my home in direct sunlight but opens them for evening time or cloudy days.

With some experimentation I got it tuned to the numbers so accurately it works precisely as I desire. Always opens and closes just when I intend.

 

[johnlaroux]

Heres an example of a light sensor. You would have to make an enclosure to house it. http://www.robotshop.com/dfrobot-ambient-light-sensor-1.html

 

[jeangv]

Perfect! Any ideas on how I can make an enclosure with a window for the photo sensor? This will be for outdoor use to go on the roof of my house to face the sky.

 

[jeangv]

chedemefedeme, I bought an ELK M1 and what to set it up as a light sensor.
 
You had posted some time back that you wired in a photoresistor into your ELK M1. I want to do the same to measure outdoor light intensity via a program on the M1. Can you give me any details on what you used and how it was configured?
 
Thanks!
Jean-Marie Vaneskahian
[email protected]