Difference between revisions of "Add-On Services"

Revision as of 21:01, 23 January 2013

Meteobridge provides some additional services, which might be interesting, when you also want to use received data with your own postprocessing IT. Live data can be derived in two ways. Meteobridge client can be asked by a HTTP request to return data (pull mode) or can send data as HTTP-GET requests with user-defined URL parameters to a user-defined Internet address (push mode).

Pull Mode

Web server of Meteobridge client, which presents web interface for adminstration to you, can also deliver weather data. There are two URLs defined that can be polled to get most recent sensor data in XML or plain text. Although we don't recommend this for security reasons, you can make that URLs accessible from the Internet by configuring your router appropriately. However, when you want to bring sensor data to one of your own servers in the Internet we recommend to make use of Meteobridge's push mode, which will not need you to open up your firewall.

Live Data as XML

By sending the meteobridge a HTTP request like "http://ip-of-meteobridge/cgi-bin/livedataxml.cgi" (where "ip-of-meteobridge" must be replaced by the IP itself) meteobridge returns current weather data in XML notation. Each reply starts witch tag <logger> and ends with </logger> with the sensor data as records with sensor specific tags "THB", "TH", "WIND", "RAIN", "UV", "SOLAR". Example below illustrates the XML format:

<logger>
  <THB date="20121227224318" id="thb0" temp="26.0" hum="37" dew="10.2" 
       press="1008.8" seapress="1010.1" fc="2"/>
  <TH date="20130104141909" id="th0" temp="9.1" hum="95" dew="8.3"/>
  <RAIN date="20130104141856" id="rain0" rate="0.0" total="3.0" delta="0.0"/>
  <WIND date="20130104141916" id="wind0" dir="109" gust="0.9" wind="2.2" chill="9.1"/>
</logger>

Each sensor data record has a mandatory "date" and "id" parameter. The other parameters are sensor specific. Meaning of parameters is:

• date: UTC timestamp of reception of sensor data in format "YYYYMMDDhhmmss"
• id: Unique ID of sensor, consists of a sensor type description shortcut followed by a number, which is always "0" in Meteobridge, as additional sensors are not supported
• temp: temperature in degrees Celsius (with one decimal)
• hum: relative humidity in percent (no decimals)
• dew: dew point temperature in degrees Celsius (with one decimal)
• press: station pressure (without altitude correction) in hPa (with one decimal)
• seapress: normalized pressure with altitude correction (also called sea level pressure) in hPa (with one decimal)
• fc: stations forecast code, if provided. As this has low evidence and also largely varies between stations, meteobridge does not recommend to make use of this data.
• rate: measured rain rate in mm per hour (with one decimal).
• total: current value of rain bucket counter, converted to mm (with one decimal).
• delta: additional rain fall in mm since previous readout of this data (with one decimal).
• wind: current average wind speed im m/s (with one decimal).
• gust: curent not avergaed wind speed in m/s (with one decimal).
• dir: wind direction in degrees (0-359, no decimals).
• chill: wind chill temperature in degrees Celsius (with one decimal).
• more to come...

Live Data as Plain Text

By sending the meteobridge a HTTP request like "http://ip-of-meteobridge/cgi-bin/livedata.cgi" (where "ip-of-meteobridge" must be replaced by the IP itself) meteobridge returns current weather data as plain text. Each reply consists of a series of lines, where each line represnets a sensor. Lines do start with a time stamp and a unique sensor id followed by sensor specific parameters. Example below illustrates the format:

20130104142614 thb0 26.9 38 11.4 1020.4 1021.7 2
20130104142610 rain0 0.0 3.0 0.0
20130104142636 th0 9.1 95 8.3
20130104142652 wind0 160 2.2 1.8 8.0

Push Mode

When you select expert mode at the bottom of "Upload Data" tab, you will see an additional entry that allows you to send sensor data to a user-defined server.

Individual HTTP Upload

Data will be sent as HTTP GET requests with URL parmeters you can define to your liking. Parameters of a URL consist of name-value pairs seperated by '&'. You can define names yourself and can use a certain set of variables provided by Meteobridge to be used as values. Variable names will be automatically replaced by their current values, each time a HTTP request is sent. Please have a look at the example below.

Upload schedule is defined to every 5 seconds. URL specifies server address, where to deliver data ("http://myserver.com/upload.php" in the example above). "Success Condition" allows to specify a matching string which is compared to to the return message from the server to decide if upload was successful or not.

Weather data is transported to the server by means of URL parameters. Meteobridge provides a large set of variables that can be used to feed URL parameters with current sensor data. Section "Templates" will explain how to use these variables to fill URL parameters with recent sensor data.

Templates

Meteobridge provides a very flexible mechanism to smuggle sensor data of different kinds into strings to be uploaded to a private Internet server or to a twitter account. Simply type in the text you want to upload and represent the pieces of sensor data by so called variables. When data gets uploaded, these variables will be replaced by current sensor data and so a string filled with the data you intended will be uploaded.

sensor-selector=converter.decimals:replacement

"converter", "decimals" and "replacement" can be omitted, "sensor" and "type" are mandatory. While "sensor" tells what sensor and what piece of information of the sensor to use, "selector" decides data from what time period should be taken into account and "converter" does convert data into measurement units the user likes most. "Decimals" decides about precision the result should be shown in and "replacement" gives the string to be returned when there is no data for defined sensor available.

Sensors

These sensors are defined in Meteobridge.

• th0temp: outdoor temperature in degrees Celsius
• th0hum: relative outdoor humidity as percentage
• th0dew: outdoor dew point in degrees Celsius
• thb0temp: indoor temperature in degrees Celsius
• thb0hum: indoor humidity as percentage
• thb0dew: indoor dewpoint in degrees Celsius
• thb0press: station pressure in hPa
• thb0seapress: normalized pressure (computed to sea level) in hPa
• wind0wind: wind speed in m/s
• wind0avrwind: average windspeed in m/s (time used for average depends on station)
• wind0dir: wind direction in degress (0° is North)
• wind0chill: wind chill temperature in degrees Celsius
• rain0rate: rain rate in mm/h
• rain0total: rain fall in mm
• uv0index: uv index
• sol0rad: solar radiation in W/m^2

If a sensor is not there or data of sensor has passed the "tolerated data age" interval, Meteobridge will not provide data for it and will present the value defined as "replacement". If no replacement is given, variable will not be converted into data but will stay as is.

Selectors

Sensors are followed by a selector (syntactically separated by a dash) that specifies what period in time should be used for evaluation. Valid selectors are:

• act: most recent data
• hmin: minimum value of this hour
• hmax: maximum value of this hour
• dmin: minimum value of today
• dmax: maximum value of today
• mmin: minimum value of this month
• mmax: maximum value of this month
• hmin: minimum value of this year
• hmax: maximum value of this year
• hmin: minimum value of all time
• hmax: maximum value of all time

Apart from selectors that use absolute, predefined time slots there are also selectors that look for a certain amount of time into the past.

• max2, max5, max10, max15, max30, max60: selects the maximum value from the last 2, 5, 10, 15, 30 or 60 minutes
• min2, min5, min10, min15, min30, min60: selects the minimum value from the last 2, 5, 10, 15, 30 or 60 minutes
• avg2, avg5, avg10, avg15, avg30, avg60: selects average value from the last 2, 5, 10, 15, 30 or 60 minutes
• sum2, sum5, sum10, sum15, sum30, sum60, sumday: selects summerized delta values from the last 2, 5, 10, 15, 30, 60 minutes or current day (useful to get amount of total rain in a certain time frame: "rain0total-sum60" is rainfall im mm of last 60 minutes, "rain0total-sumday" is todays rain fall)

Converters

Sensor data is reported in ISO units (°C, hPa, mm, m/s) by default, but can be converted into non-ISO units (imperial) by adding a conversion token. Defined tokens are:

• F converts temperature from Celsius to Fahrenheit.
• psi converts pressure from hPa (equivalent to mbar) to psi.
• mmHg converts pressure from hPa to millimeters of mercury.
• inHg converts pressure from hPa to inches of mercury.
• kmh converts wind speed from meters per second to kilometers per hour.
• mph converts wind speed from meters per second to miles per hour.
• kn converts wind speed from meters per second to knots.
• bft converts wind speed from meters per second to Beaufort scale.
• in converts millimeters to inches.

If an unknown conversion string is used, no conversion will take place, no error message will appear.

Special Variables

There are a couple of variables that don't come as "sensor-selector=converter" chains but have a distinct meaning by themselves.

Date und time variables are defined as follows:

• YYYY: year as four digit number
• YY: year as two digit number
• MM: month as two digit number, if only one digit neede a zero will be used as first digit
• M: month as one or two digit number, no leading zeros
• DD: day of month as two digit number, if only one digit neede a zero will be used as first digit
• D: day of month as one or two digit number, no leading zeros
• hh: hour as two digit number, if only one digit neede a zero will be used as first digit
• h: hour as one or two digit number, no leading zeros
• mm: minute as two digit number, if only one digit neede a zero will be used as first digit
• m: minute as one or two digit number, no leading zeros
• ss: seconds as two digit number, if only one digit neede a zero will be used as first digit
• s: seconds as one or two digit number, no leading zeros

When a capital "U" preceeds a date/time variable name, UTC is used instead of local time ("[Uhh]:[Umm]:[Uss] UTC" is evaluated to a string like "16:03:33 UTC")

Decimals

Unless otherwise defined numbers are reported with one decimal. By specifying a value for "decimals" you can determine resolution of presented values.

Replacement

When a variable is not defined or there is no data for a specified sensor, information specified as "replacement" string will be represented instead.