Which temperature sensor to buy....

Forum 2005-2010 (read only) Hardware Interfacing
1

I've read about LM34's and LM35's and there are others at Jameco.com. Which one do I wanna buy? I'd like good precision and need to interface with Arduino. I saw some analog ones and don't know what that means from an Arduino perspective.

NOTE - I think I want an LM34 which outputs F instead of C. Anyway, there are some sensors that have an output type of "voltage" and others have an output type of "analog". Do I want the analog one or voltage one for use with Arduino. Geeze, I just wanna get the right one.

2

The Maxim ones rock! :slight_smile:

3

Thanks but that doesn't really help me :slight_smile: I wanna get a LM34 as I've seen may tutorials using this one but if I search for LM34 I get 100 different types. I wanna make sure I get the right one. Jameco ships same day and need it pretty quick unless someone can point me somewhere that ships just as fast.

4

Not sure.

I like the Maxim one because you communicate with it digitally - therefore you get a figure in C or F back rather than an unknown range.

5

Well, LM34/LM35 are Degrees F/Degrees C. So there's your first answer. IF you want Degrees F, you wan the LM34.

Now, I think that the easiest package to use is the TO-92 package. (like a small signal transistor package). That's the LM34DZ or LM34CAZ.

Of the two, I'd pick: LM34DZ About $2.00 from Jameco.

6

Do you have to offset these devices for negative temperatures?

7

You need to be careful about the range of temperatures that you want to measure, some of the LM34s/35s only do 0-100c, so look at the datasheet carefully, I believe there is a letter designation but can't confirm which is which, but it would be something like LM35D or DZ etc.

I'm currently using some dallas DS18B20 1wire sensors, they're digital like the 'maxim' ones that have been mentioned, the beauty of them is that they are digital and you can hook many of them up to the same digital pin, currently got 3 running from the same pin. There is also a nice library for them too :slight_smile:

I'm also using a sensiron SHT11 temperature and humidity sensor, a nice digital temperature and humidity sensor. Both types of sensor are nice, relatively cheap too