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    • MacGyver style sensor Hack-a-ton, friday afternoon at #AGU15

      December 16, 2015 | English | Rolf Hut
    • Ever measured pressure using a soda can? Ever used your own hair as a humidity sensor? Ever measured temperature with your watch? Yes: we need you! No: this will be your first time.

      This Friday we will hold a MacGyver-style hackathon in which you will build a device using cast-offs donated by the exhibitors at this year's AGU fall meeting.

      This hackathon was inspired by the MacGyver poster session on Tuesday, where scientists presented their custom-made, hacked, and tinkered devices to overcome measurement problems in their studies. For inspiration on the kind of atmosphere we are trying to achieve, see the "5 experiments in 5 minutes" video below, or the example by Pete Marchetto at the end of this post.

      What:
      A 2-hour rush to build a device from cast-offs

      Where:
      At the base of the entrance escalators in Moscone North

      When:
      Friday, Dec. 18, 13:30-15:30 PT

      Who:
      Anyone interested! MacGyver skills not required; you will learn on the job

      Prize:
      Bragging rights and all the swag that you can haul from the leftovers.

      E-mail if interested to r.w.hut@tudelft.nl.

      example by Pete Marchetto
      I wanted to measure temperature, but all I had was this little blinking LED that I picked up from the AGU Poster Helpdesk here at the Moscone Center. Without removing it from its little plastic bag, I put it in a paper cup and put my phone on top of it to take a ten second video, seen below:

      I then put some ice on top of it and waited for about a half hour for it to come down to temperature. I then shot a quick video of that for ten seconds:

      I counted the number of blinks from the room temperature movie, and came up with 26, which is 2.6 Hz. I then counted the same from the freezing movie, and got 29, which is 2.9 Hz. This gives me a frequency dependence of 0.015 Hz/°C, given room temperature of ~20 °C and freezing point of ~0 °C.

      This tells me two things: first, that the blinker circuit is an RC circuit (because R~T and RC=1/f), and second that I can use this as a pretty accurate thermometer, if only the movies that I take of it are long enough.