Sensorcast Weather Station(s)

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Measuring environmental conditions is typical of the kinds of data we always envisioned collecting and managing, so the Sensorcast Weather Station was one of the 1st set of sensors we started our experiments with.

We actually have 2 full-time co-located stations reporting distinct sensor data.

Stations

sensorcast-weather-001

This was our 1st station and we built it from scratch utilizing 1-Wire components from Hobby Boards and help from Weather Toys (the book). The station equipment is wired to a laptop via a Cat-5 cable, a 1-Wire serial adapter, and a USB to serial converter.


sensorcast-weather-002

Our second station is a Davis Instruments Vantage Pro2. This station has a wireless console which has a proprietary expansion connector in the rear. It has been hacked/adapted to allow it to be wirelessly controlled via USB->XBee->XBee->Console from a computer host.

Querying the Data

Querying the data for any station is quite simple and conforms to the general procedures as described here.

24-hour Statistics

Statistical data comes directly from a primary datalogger. As such the access is very programmatic and the visualization is intended to be very basic.

Example
http://query.sensorcast.org/v1/statisticsQuery.do?stationId=sensorcast-weather-001

When using a web browser this will render a rudimentary page containing the statistics of the station for the current 24-hour period. It will be updated every 5 seconds. This can be modified using the drop down list on the page. This is not intended to be a full substitution for visualization but rather something basic and helpful.

If you query using some other user agent -- e.g., wget, curl, some application code -- you should specify the format you'd like using the HTTP header "Accept: application/xml" or "Accept: application/json".

Downloading Data

Example
http://query.sensorcast.org/v1/dataQuery.do?stationId=sensorcast-weather-001[&startTime=YYYY/MM/DD HH:MM][&endTime=YYYY/MM/DD HH:MM][&format=[text|xml|json|csv]][options=[as-file],[with-headings]]

Parameters

startTime/endTime

The default startTime is 00:00:00 (today) and the default end time is now, or startTime + 24hours if startTime is more than 24-hours from now. So the request:

http://query.sensorcast.org/v1/dataQuery.do?stationId=sensorcast-weather-001&format=text&options=with-headings

will produce a page of text of Comma Separated Values (CSV) with column headers with values/readings since midnight (00:00:00) of the current day. If you want the values as a file set format=csv.

NOTE: The primary datalogger, or collection system, is limited to querying data in 24-hour intervals to avoid extraordinary resource intensive conditions which can effect the entire system. The archive systems generally have less restrictive rules.