Retrieve sensor observations

Description

This action allows you to retrieve the latest observations of a sensor. In addition, the service can also permits to specify search criteria to retrieve observations: filter by a given time period and / or to indicate the maximum number of observations to be retrieved.

http://<your_api_server.com>/data/<provider_id>/<sensor_id>?<parameter>=<value>

Format	json
Method	GET
Permission	Reading
Returns	Observations list

Parameters

Key	Description	Optional
from	Indicates the beginning of the time period for which you want to retrieve observations	Yes
to	Indicates the end of the time period for which you want to retrieve observations	Yes
limit	Indicates the number of observations to retrieve	Yes

Please, note the following:

• The maximum number of records returned will be fixed by the platform settings. If the parameter passed is higher, the number of records returned will be equals to the maximum value configured in the platform.
• If the limit parameter is not set, only one observation will be returned.
• All dates must have the following format: dd/MM/yyyyTHH:mm:ssZ with Z as optional (and with default value UTC)

Response data

As mentioned, in addition to HTTP status code, the observation data is returned in the body contents as a list of observations:

Key	Description	Optional
observations	List the observations (observation)	No

Each observation has the following structure:

Key	Description	Optional
value	Observation value	No
timestamp	The time when the observation was made based on UTC (dd/MM/yyyyTHH:mm:ss format)	No
time	The time when the observation was made in milliseconds	No
location	Geolocation coordinates in which the sensor was recorded observation	Yes

Examples

Request to retrieve the latest observations of a sensor based on a date

The following request shows an example in which a call is made to retrieve the last 20 observations of the sensor with RE0012 identifier of the provider named rec which have been registered from 10/01/2013.

http://<your_api_server.com>/data/rec/RE0012?limit=20&from=10/01/2013T10:00:00

As response we receive:

{"observations":[
   {
      "value":"28.61132406103821",
      "timestamp":"13/11/2017T09:00:00",
      "time":1510563600000

   },{
      "value":"20.795568440010314",
      "timestamp":"13/11/2017T08:30:00",
      "time":1510561800000
   },{
      "value":"91.01094902496055",
      "timestamp":"13/11/2017T08:30:00",
      "time":1510561800000
   },{
      "value":"62.22915604583776",
      "timestamp":"11/01/2013T08:16:38",
      "time":1510561800000
   },{
      "value":"99.96065618303348",
      "timestamp":"11/01/2013T07:16:38",
      "time":1510561800000
   },{
      "value":"94.95685904585568",
      "timestamp":"11/01/2013T06:16:38",
      "time":1510561800000
   },{
      "value":"51.26506022800391",
      "timestamp":"11/01/2013T05:16:38",
      "time":1510561800000
   },{
      "value":"21.43303677241535",
      "timestamp":"11/01/2013T04:16:38",
      "time":1510561800000
   },{
      "value":"55.6601921120059",
      "timestamp":"11/01/2013T03:16:38",
      "time":1510561800000
   },{
      "value":"56.692086830598996",
      "timestamp":"11/01/2013T02:16:38",
      "time":1510561800000
   }
]}

Request to retrieve the last observation of a sensor

If you only want to retrieve the last observation of the RE0012 sensor, the request to do is:

http://<your_api_server.com>/data/rec/RE0012

As response we will receive:

{"observations":[{
   "value":"11.5",
   "timestamp":"18/09/2012T17:20:00",
   "time":1510561800000}
]}