Smiffy's Weather Station

My current weather station (January 2005) comprises the following:

  • Home-made 1-Wire® adapter: DS2480B + MAX232 + DS9503. The adapter board is mounted in the casing of an old D-Link ethernet hub, which provides the power supply and front panel jacks. All the jacks are wired in parallel, giving a star topology for the temperature sensors, which are connected through the CAT5E house structured cabling. One leg of the star goes out through the wall on twisted pair telephone cable to the rain gauge and weather instrument. I have had no problems with this arrangement except once when one of the cable joints was attacked by birds.
  • AAG Weather Instrument. The temperature sensor in this unit is
    recorded but not reported. The weather instrument is attached
    to a piece of galvanised box section, currently tied to one of
    the (steel) posts of a panel fence. This needs slight re-orientation
    and raising as far as I dare without things wobbling about too much.
  • Lacrosse rain gauge – originally wireless, but with all the guts
    ripped out and replaced by a home-made board with a DS2423.
    Circuit based on Dallas application note. I used the wireless gauge
    because the [tipping] bucket had a better resolution (0.01 inch/0.254mm)
    than the wired unit that was offered.
  • 6 1-Wire® temperature sensors – various models. These are
    distributed around the house, with one outside. The outside unit
    currently reads high when the sun is on it since it’s located
    in a plastic flower pot rather than a Stephenson screen!

Future additions to the station – some sooner, some later, some maybe never:

  • DS2423-based lightning detector
  • Temperature probe in my beer fermenter.
  • Airlock ‘glug’ count for beer fermenter (DS2423 and some kind of optical
    sensing) to determine fermentation rate.
  • Field mill for measuring cloud (electrostatic) charge. Have yet
    to settle on an interfacing technique for this – will either
    use 1-Wire® analogue to digital convertor (DS2450) or just run
    the whole thing off a microcontroller and present data through
    a 1-Wire® port expander (DS2408).
  • Geomagnetic sensor; sensor and processing chip (SCL006B) from
    Speake Sensors;
    processing chip has digital out so will probably interface to
    a DS2408 port expander.
  • Atmospheric pressure (DS2450 + ?)
  • Relative humidity (DS2450 + ?[2])
  • Insolation (some sort of differential arrangement with DS18B20)
  • Some sort of optical system to check the clarity of the irrigation water
    coming out of our aerobic wastewater system (DS2450).
  • Temperature probe in septic unit of aerobic wastewater system.
  • pH probe in septic unit of aerobic wastewater system.