Temp and Humidity sensor 1-5V output

Discussion in 'The Projects Forum' started by bowlingo, Feb 5, 2012.

  1. bowlingo

    Thread Starter Member

    Jun 29, 2011
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  2. bowlingo

    Thread Starter Member

    Jun 29, 2011
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  3. wayneh

    Expert

    Sep 9, 2010
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    For temperature I'd consider a much cheaper approach, a thermometer IC such as the LM35. The specifications for the device address accuracy, and perhaps it's good enough for you.

    Humidity is tougher. Most home units use a plastic strip that changes size depending on ambient humidity, tripping a mechanical switch. But there are better approaches. In industrial controlled-environment rooms, I've seen genuine wet bulbs, which of course have to be maintained with fresh water. They're nice because you don't need to calibrate a humidity sensor - just the temperature probe.
     
  4. BSomer

    Member

    Dec 28, 2011
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    Last edited: Feb 6, 2012
  5. bowlingo

    Thread Starter Member

    Jun 29, 2011
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    The one on the mikroelectronica site would be ideal but the only way I think i can get it to work is by putting the board in a small adapatable box with vent holes in then wire it back to the picplc...would need to be about 5-10 metres...do you think its possible

    http://www.mikroe.com/eng/downloads/get/1547/sht1x_manual_v100.pdf

    Thanks
     
  6. BSomer

    Member

    Dec 28, 2011
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    I don't think that remote mounting of the sensor would be a problem. I would use some sort of shielded cable to help eliminate emi or other interference. They also have another sensor that comes without the dip switch and is smaller. That one could go in a really small enclosure.

    I only suggest the ones from mikroe because of available library examples and being compatible with your specific mcu without modification.
     
  7. MrChips

    Moderator

    Oct 2, 2009
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    Vaisala and Honeywell make temperature and humidity sensors but they're not cheap.
     
  8. bowlingo

    Thread Starter Member

    Jun 29, 2011
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    Hello,

    Where is the one without the dipswitch on the mikroelectronia site?
     
  9. nigelmercier

    New Member

    Oct 9, 2010
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    IMO it's easier, cheaper and better to use a sensor with a digital output.
     
  10. bowlingo

    Thread Starter Member

    Jun 29, 2011
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    I e-mailed mikroelectronica and they are saying this will work...add on board, in adaptable box on long cable...

    Any ideas on a 10m screened cable type to use?

    Thanks
     
  11. BSomer

    Member

    Dec 28, 2011
    433
    106

    http://www.mikroe.com/eng/products/view/368/sht1x-proto-board/

    As to the cable...

    Well it is really up to you how you do it. I think that any shielded cable would do fine as long as it has the correct amount of conductors in it. I think you only need 4. You may be able to get away without the shield and use something like CAT5 networking cable. Build it up with that and test it to see if you are getting any errors in the data. If you have no errorsm you are good to go. :)

    Brian
     
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