using a thermal chip for Temperature

I see that there is coding for changing the input value to a temperature
Not sure how the thermal chips work
I was thinking that they would work like a photo sensor the input value would change as the temperature changes
I want to operate a relay at a specific temp so I was hoping that I could watch the value go up or down using the monitor and then using a digital thermostat just take note of the value when the thermostat is at the desired temperature. Then use that value in my sketch
or is there a better way
Thanks

Since you have given no part number I have no idea what your talking about.

Ok sorry
I was going to use this for temperature
DS18B20 Digital Temperature Sensor
So not having one Im wondering if they work the same as a Phote sensor in the way that the Arduino board reads the input
that way using arduino monitor I can watch and see what the value is for say 71 degrees

Can you post a link to the datasheet?

Have you Googled to see if someone else has already used this with an Arduino?

...R

Phote sensor

Do you know of any ONEWIRE photo sensors ?
I am quite familiar with the DS18B20 .
If you want to know if this is an analog or digital sensor why don't you just ask THAT question ?

Well cause I didn't know enough to ask sorry. I now am assuming that not all temperature sensors work the same. I dont have one yet so maybe you can recommend one to get.
the data sheet is here

So looking at the data sheet Im assuming that you apply 5v to the outside pins and then the DQ pin goes to the Arduino and Im assuming that like a photo sensor the input value changes with the temperature like the photo sensor and the amount of light

I don't need the datasheet.
Really the only thing I need to know is if you intend to use in an application where it will be submerged in water or some liquid.
If not then any DS18B20 will do and they are readily available from a multitude of suppliers.
You need to be aware that it is digital so forget about using an analog input . (you wouldn't be the first to have tried)

Ok so its not analog like the input from a photo sensor where the voltage changes on the output according to the amount of light that it senses. So the only way to use the temperature sensor is to download the library from the manufacture to convert the digital input to degrees.
Oh and no liquid just air

is to download the library from the manufacture to convert the digital input to degrees.

Well no, not exactly. You do need the library (unless you can bit bang it yourself, which I don't think is the case) but it is not from the manufacturer. Generally they don't write libraries, (from their point of view that is the user's problem) So there are two libraries
but the easiest for a newbie would be the Dallas Temperature Library. The code is much simpler than the ONEWIRE library, but I believe you need to load both of them so the Dallas Temp Library can utilize the ONEWIRE library. (sort of case of a library to use a library).

http://playground.arduino.cc/Learning/OneWire

How many sensors ?
Don't forget the 4,7k ohm pullup resistor from the Data out pin to +5Vdc.

Thanks
So I would load this code at the beginning of my sketch

If you take the time to actually look at the library after you install you will find it is full of working examples so you don't really have to do anything in the way of coding other than understand how to use the 64-bit ROM address to tell the library how to find YOUR specific sensor. If you only have one sensor you can use the example, but if you have more than one and you want to display ONE of the temps and NOT the other, do you know how to tell the library WHICH sensor to display ? (on an LCD for example)

Ok thanks for that I only have one sensor
Rick