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Need Outdoor Temp/Hum Sensor

TurnipTruckTurnipTruck Posts: 1,485
in AMX General Discussion
Greetings,

I am looking for an outdoor temp/hum sensor for a system. Nothing fancy or expensive. I looked at the HAI 31A00-7, but cannot come up with a protocol sheet to know how to talk to it.

Any ideas?

Thanks.

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    viningvining Posts: 4,368
    TurnipTruck wrote:
    I looked at the HAI 31A00-7, but cannot come up with a protocol sheet to know how to talk to it.
    I'm pretty sure they don't talk, just +- power and a wire for temp and another for humidity. My guess is they vary the voltage to the Omni controller and if a security zone is configured for temp or humidity it runs an algorithm or compare the value to a look up table to convert the voltage coming in to the correct human readable value.

    If you could get a hold of a conversion chart you could probably use an NXC-VAI4 to recieve the voltage and create your own look up table or do math to convert to a readable value.

    There's got to be other products out there but I'm drawing blanks.
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    annuelloannuello Posts: 294
    This company may be able to help. http://www.hw-group.com/products_monitoring_en.html#humid Never dealt with them before, so I don't know if they fit the "nothing expensive" category or not. I can't see documentation for their RS485 bus, but they may provide it if you ask.

    I'm interested in how you get on with it, since I want to do some humidity control at home. I bought one of these (http://www.futurlec.com.au/Temperature_Sensors.jsp) a few years ago, but still haven't got around to putting it into a micro circuit to make it useful.

    Roger McLean
    Swinburne University
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    yuriyuri Posts: 861
    http://www.papouch.com/en/products.asp?dir=thermometers

    there you go :)
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    viningvining Posts: 4,368
    FYI, the info I got from HAI states the HAI temp/humidity sensor actually transmit as a varying frequency. This actually makse sense since a varying voltage could have errors induced from any EMI source or even the variations of cable length.
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    DHawthorneDHawthorne Posts: 4,584
    I've successfully used the HA7Net OneWire interface with a temperature probe. I use an IP connection to grab the web interface and parse that. It can be expanded quite a lot at minimal expense.
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