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Twine Operating Temperatures?

anthony melisanthony melis
edited November 2012 in At home Vote Up0Vote Down
I am trying to use Twine as an alarm for a freezer temp. The freezer operates in the 0-10 degree Farenheit category. I'm kind of noticing if Twine gets too cold it stops updating. Is there a known miniumum operating temp of Twine.

Answers

  • 5 Comments sorted by Votes Date Added
  • Bob StemenBob Stemen
    Vote Up1Vote Down
    Anthony,

    I am doing the same thing and had the same problem but it was not due to temperature it was a hiccup in the twine updating through my network. I gave my Twine a static IP address per the support site and it had been updating at 45 second intervals ever since.

    Now I am in the process of reducing the set point of the alarm so that I get a quick notification but no false alarms. I need to take it out of the freezer once to see how long it takes the temperature sensor to warm up to the alarm point.

    My freezer seems to be running at -2 to +1F.
  • John AmschlerJohn Amschler
    Vote Up0Vote Down
    Theory: Twine not working in the Freezer may be VBatt/Voltage Regulator issue, not a wireless connectivity issue.

    I had my twine in the freezer all day running on the internal batteries - I checked it 4 hours after I put it in there and there were no updates (I didn't check wireless connectivity, because I had to head out to work...)

    When I got home I took Twine out of the freezer, turned it over and in about 30 seconds it started flashing and updated the site. Next I put the twine back in the freezer and it stopped communicating again.

    In order to debug this I decided to place the Twine in the freezer and then run a long USB cable out to my Newtrent Charging Battery.

    This has been working for the last 30 minutes - temp is 7F, Voltage is 2.82V.

    @Anthony - your issue may be temperature related, much like mine was.

    @Bob - how are you getting 45 second updates? Why do you thin the static IP solved this?
  • Gerry MuellerGerry Mueller
    Vote Up0Vote Down
    Freezers typically run at about -20 C (-4 F), so you'd want an alarm that your freezer has stopped working at probably -10 C (14 F). Putting the Twine in the freezer seems problematical, given it's operating temperature limits, battery issues, getting WiFi signal in a metal cabinet.
    But you can use the break-out board to connect the element out of an old thermostat. This is a bimetal coil thermometer, fixed but rotatable at the centre, and a mercury switch at the free end. The temperature at which the switch closes is set by rotating the entire element. The element would have to be mounted vertically on a freezer wall, and the position of the element would have to be determined by experiment. The movement of the coil is roughly linear with temperature, so could get a rough calibration by noting where the switch is at proper freezer temperature and at know room temperature, and interpolating for the alarm temperature
    Another solution that comes to mind is a simple block heater thermostat. For those not living in northern climates, these are a small cube that plugs into the wall, and has an outlet for a car block heater. At some (usually fixed, but in some higher-priced models moderately adjustable) these switch on the block header. In effect, they simply establish a connection between the live pin on the plug-end. and the live outlet on the outlet-side. Just what you can use with the break-out board to have a signal that goes from "closed" to "open" if the temperature goes above the set temperature.
    there may be an issue with power consumption. When any of the sensors is at "closed" there is more drain on the batteries. If this is a serious issue for this kind of use, then some simple electronics can be build to reverse the thermostat signal.
  • John AmschlerJohn Amschler
    Vote Up0Vote Down
    After more testing I've realized that this problem is not exclusively due to a temperature/voltage problem, it may be a combination of signal strength, resetting and IP issues caused (potentially) when using DHCP
    -OR-
    it could simply a web server issue that is periodically crashing/overloading

    They said they had to debug the internet... so I'm leaning toward that a bit since my temperature updates quite often on my twine.supermechanical.com page!



    I believe this because:

    1. It appears that the attaching the USB cable and the Newtrent external Battery improved the antenna efficiency.
    2. It also appears that attaching the USB cable to the Twine only increases the antenna efficiency.
    3. Setting the Twine next to my AP still results in data dropouts / system reset (?)/ twine web API issues.

    Any of the above mentioned issues may be red herrings to the true issue ;)


    NEXT STEP:
    Static IP address - it worked for one other person! http://community.supermechanical.com/index.php?p=/discussion/comment/333#Comment_333
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