Could someone help me with the questions about light sensor?

Hello~
I'm working on a building automation control project. I need to select a sensor to detect light level of a room. When I search for light sensor on alibaba, there are various outputs, such as, digital sensor, switching transducer and analog sensor. I'm new in this field.

Could I use the light sensor has a output of switching transducer to communicate with Micro-controller for detecting light level purpose?
Could anyone help me to clear the use of these three outputs?

Thank you in advance!

Hi

The simplest sensor and also the cheapest I could think of is an LDR( Light Dependent Resistor). Here is a implementation of that in an Light Level Application: http://www.technologystudent.com/pics/drksen1.html

For your question, It is possible to use the light sensor as an output of a switching transducer to communicate with microcontroller.

The switching transducer probably acts like a switch where above some predefined light level the contacts are closed and below that level they are open (or the other way around). It is only useful for sensing whether you are above or below a predefined threshold.

An analog sensor will produce a signal that is variable and proportional to the about of light.

Digital could be either one.

Think of them like this: A switching transducer is like a thermostat, it can turn something on or off at a specified temperature. An analog sensor is like a dial thermometer, it reads out the actual temperature. A digital sensor could provide a on/off threshold output, or a data stream that has the current temperature encoded in it. Light sensors provide basically the same outputs.