Monitoring multiples temperature sensors.

Hello. I'm hoping someone can offer me some advice or possibly some sources to point me in the right direction. I am very new to electronics and programming but thought this might be a pretty simple project to get started. I have a friend who owns reptiles and has a fairly large enclosure in which he wants to be able to monitor the temperature in different locations. What I had in mind was an arduino with an LCD display that will show the temp on 4 different sensors. What I'm looking for is an idea of what components, ie. shields, sensors I would need to accomplish this and maybe some ideas on code to get everything working. Right now I have an arduino duemilanove to build off of. Thanks in advance for the help.

If there will only be 4 temperature sensors, you could use 4 x LM35 sensors. These would use 4 analogue inputs, 1 per sensor.

That still leaves A4 and A5 for I2C use (possibly for the LCD?).

How far apart do the temperature sensors need to be?

Mountsj:
. What I had in mind was an arduino with an LCD display that will show the temp on 4 different sensors. What I’m looking for is an idea of what components, ie. shields, sensors I would need to accomplish this and maybe some ideas on code to get everything working. Right now I have an arduino duemilanove to build off of.

If your are OK with a range of -55 to 135C, I submit you would do well to use the DS18B20 temp sensors. They are popular, cheap, easy to use, and well supported on this forum. These devices can all share one pin. Now, since you have “only” four sensors in mind, this might not seem such a big deal but one of the things you will quickly learn about Arduino is the amazing speed at which you can run out of pins, and I don’t know why you would consider any other sensor.

All you need to know is here

http://www.hacktronics.com/Tutorials/arduino-1-wire-tutorial.html

There are shields that can take the sensors but you might be better off making your own. That way, you are not constrained by their choice of plugs. Pic shows a shield with on-board clock and terminals for 3x DS18B20, a flow meter, a 4x20 LCD, and a bluetooth module.

shield.jpg

Does this look like something that might work? I just built it and it works great.

http://arduino-info.wikispaces.com/MultipleTemperatureSensorsToLCD

I would second (or third?) the use of the DS18B20. It provides the temperature as a digital value so there's no need to mess around with analog conversions.

Pete