Sensor Measurements List (SenML) Support

The Sensor Measurements List (SenML) format is designed so that the processors with very limited capabilities can easily encode a sensor measurement into the media type, while at the same time, a server parsing the data could collect a large number of sensor measurements in a relatively efficient manner.

SenML are used to represent the data to/from constrained devices in a concise format. LWM2M 1.1 supports SenML in the following two formats:

  • SenML CBOR - Content format used to represent data in binary, which has data type information of the Object / Resource model encoded.

    Sample format:

    [{-2: "urn:dev:ow:10e2073a0108006:",
    -3: 1276020076.001, -4: "A", -1: 5, 0: "voltage", 1: "V", 2: 120.1},
   {0: "current", 6: -5, 2: 1.2}, {0: "current", 6: -4, 2: 1.3},
   {0: "current", 6: -3, 2: 1.4}, {0: "current", 6: -2, 2: 1.5},
   {0: "current", 6: -1, 2: 1.6}, {0: "current", 6: 0, 2: 1.7}]
  • SenML JSON - Content format used to represent data in JSON, which has data type information of the Object / Resource model encoded.
    Sample format: 
    [{ "n": "urn:dev:ow:10e2073a01080063", "v":23.1, "u":"Cel" }]