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Using Twine with a current sensor to get alerts when my sump pump runs.

Martin CowleyMartin Cowley
edited November 2012 in At home Vote Up1Vote Down
I've always been curious as to how often my sump pump runs. Now that my Twine with breakout board is hooked up to an AC current sensor, I get alerts whenever it does run. All I need now is the ability for the Twine to post on Twitter and I'll be all set.

Answers

  • 8 Comments sorted by Votes Date Added
  • Bill SpencerBill Spencer
    Vote Up0Vote Down
    I guess I don't understand the difference between an SMS text from Twine and a twitter text.

    Also, can you tell us what AC current sensor you're using?
  • Martin CowleyMartin Cowley
    Vote Up0Vote Down
    No difference - I'm currently getting email alerts successfully. I just find it amusing that my sump pump could be posting to Twitter, that's the main reason, plus the fact that with it on Twitter it will be easy to review an event history.

    The AC current sensor is http://www.phenixcontrols.com/Current_Sensor/9153/. I had to split the power cable to my sump so that only the hot (or neutral) wire went through it, so I just got a Leviton electrical plug (http://amzn.to/Tv5z7F) to replace the original plug after splitting the cable. Only other thing I had to get was a resistor for pull up (CF14JT470RCT-ND from digikey.com).

  • Bill SpencerBill Spencer
    Vote Up0Vote Down
    Neat. So you're powering the current sensor with the 3.3v from the breakout sensor and using the current sensor to close the circuit between IN & Gnd on the breakout, right? What's the resistor for exactly? (What would happen without it?)
  • Martin CowleyMartin Cowley
    Vote Up0Vote Down
    Right - 3.3v power from the breakout board to the power input on the current sensor, and then hooked up the Input and Ground on the breakout to the corresponding connections on the current sensor. The sensor is normally open, and closes when it detects current over some adjustable threshold.

    As for the resistor, I'm no electronics expert so about all I know about a pull up resistor is from Wikipedia, and I don't understand it well enough to explain it. The tech guy I spoke to at Phenix Controls specifically pointed out that a pull up was needed for use with the sensor, but he didn't give me any specifics. I noticed on the Twine blog about using the breakout board as a light sensor that they did the same thing - resistor between the power and input connections, and then the sensor between input and ground - so I just ordered the same resistor used in that example and it worked fine with my current sensor.
  • whataburgerwhataburger
    Vote Up0Vote Down
    That's a really good idea, I never thought of that.
  • John LaRouxJohn LaRoux
    Vote Up0Vote Down
    You could use something like this and you wouldn't need to use any voltage. Just hook up the in and gnd to this device and adjust it to close anywhere from 2.5 amp to 135 amps.

    http://www.ebay.com/itm/VERIS-HAWKEYE-H908-CURRENT-SWITCH-/190762226587?pt=LH_DefaultDomain_2&hash=item2c6a50939b
  • Martin CowleyMartin Cowley
    Vote Up0Vote Down
    I think I remember seeing this sensor when I was looking for one, but didn't see it sold as cheaply as in your link. I assume this would still require a pull-up resistor between power and input on the breakout, so the input's not floating, but it's good that it doesn't require any power while idle (I'm using a USB adapter with my Twine so battery drain is less of a concern). The only drawback I can see is that it's quite a bit larger than the one I'm using, but that's not typically going to be an issue I wouldn't think.
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