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Temperature Reading — Parallax Forums

Temperature Reading

NosePickerNosePicker Posts: 54
edited 2008-07-26 16:07 in BASIC Stamp
Does anyone here know of a device that can be used with the basic stamp to get the temperature of the area near the stamp?

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Thanks

NosePicker

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2008-07-25 16:04
    The LM34 (www.national.com/ds/LM/LM34.pdf) is the most commonly used device. It outputs a voltage proportional to the temperature. Both the Stamp Reference Manual and this (www.emesystems.com/BS2rct.htm) have useful information on using the RCTIME statement to measure small voltages. You can also use an ADC0831 analog to digital converter. There's plenty of sample programs in the "Basic Analog and Digital" tutorial downloadable from Parallax.
  • Fe2o3FishFe2o3Fish Posts: 170
    edited 2008-07-25 19:18
    My preference would be for the DS1620 -- a little more expensive but simple to hook up with far better accuracy
    than using the RCTIME statement to measure the voltage from an LM34.

    Actually, I prefer the DS1820 but... the 1-wire code can be a bit difficult to use/digest for some people.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    -Rusty-
    --
    Rusty Haddock <=> AE5AE
    **Out yonder in the Van Alstyne (TX) Metropolitan Area**
    Microsoft is to software what McDonalds is to gourmet cooking
  • Mike GreenMike Green Posts: 23,101
    edited 2008-07-25 21:28
    The BS2 can't do 1-wire protocol, only the BS2p/pe/px (with the built-in 1-wire statements) can do it.
    The DS1620 is a great suggestion, very much easier to use. I believe there's a Nuts and Volts Column
    that would include schematics and sample code.
  • Tracy AllenTracy Allen Posts: 6,664
    edited 2008-07-25 22:31
    There are other choices, for example, the TMP04 from Analog Devices encodes the temperature in "digital" form as the ratio between High and Low times of a square wave. It is available in a TO92 package.

    National Semi makes a lot of digital temperature sensors, not just analog ones like the LM34. For example, the LM75 is I2C and the LM74 is SHIFTIN, and they are <$2 each in singles. But you do have to deal with the soic package.

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    Tracy Allen
    www.emesystems.com
  • Fe2o3FishFe2o3Fish Posts: 170
    edited 2008-07-26 16:07
    And the LM73 is accurate to +/- 1C and I2C!

    Thanks Tracy! I didn't know about these others from National Semi.
    Sadly they're all SOIC or variants.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    -Rusty-
    --
    Rusty Haddock <=> AE5AE
    **Out yonder in the Van Alstyne (TX) Metropolitan Area**
    Microsoft is to software what McDonalds is to gourmet cooking
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