Toolset to Normalize SenML and other promises

SenML is an open ietf standard that defines a format for representing simple sensor measurements and device parameters in Sensor Measurement Lists (SenML) You can find the spec: https://tools.ietf.org/html/rfc8428 Becoming more and more used within the IoT Domain, as common used standard for Constrained Application Protocol (CoAP) LwM2M 1.0 (https://tools.ietf.org/html/draft-ietf-core-senml) and LwM2M 1.0 uses the actual RFC.

Also adding support for https://tools.ietf.org/html/draft-keranen-core-senml-data-ct-01

Features

• (Basic) Normalized format for SenML Records (chapter 4.6 Resolve Records), A SenML Record is referred to as "resolved" if it does not contain any base value.
• (TODO) Support Conversion between diferent representations defined in JavaScript Object Notation (JSON), Concise Binary Object Representation (CBOR), eXtensible Markup Language (XML), and Efficient XML Interchange (EXI), which share the common SenML data model.

Example 1

iex> senml_payload_rsv_rec_1 = [%{u: "lon", v: 24.30621},%{u: "lat", v: 60.07965}]
[%{u: "lon", v: 24.30621}, %{u: "lat", v: 60.07965}]
iex> ExSenml.validate_and_resolve(senml_payload_rsv_rec_1,"1234")
{:ok,
[
  %{n: "1234", t: 1559987179, u: "lat", v: 60.07965},
  %{n: "1234", t: 1559987179, u: "lon", v: 24.30621}
]}

Example 2

iex(1)> senml_payload_base_fields = [
...(1)>     %{bn: "1234", bt: 1_559_813_429, bu: "%RH", v: 20},
...(1)>     %{u: "lon", v: 24.30621},
...(1)>     %{u: "lat", v: 60.07965},
...(1)>     %{n: "tracker", t: 60, v: 20.3}
...(1)>   ]
[
  %{bn: "1234", bt: 1559813429, bu: "%RH", v: 20},
  %{u: "lon", v: 24.30621},
  %{u: "lat", v: 60.07965},
  %{n: "tracker", t: 60, v: 20.3}
]
iex(2)> ExSenml.validate_and_resolve(senml_payload_base_fields,"1234")
{:ok,
[
  %{n: "1234/tracker", t: 1559813489, u: "%RH", v: 20.3},
  %{n: "1234", t: 1559813429, u: "lat", v: 60.07965},
  %{n: "1234", t: 1559813429, u: "lon", v: 24.30621}
]}

Example 3

iex(2)> ExSenml.validate_and_resolve(senml_payload_base_fields,"9876")
{:not_acceptable, "Payload is not valid SenML"}

TODO

• [x] Basic record normalization
• [ ] Validate "n" fields caracters
• [ ] Convert Beetween formats
• [ ] Proper Documentation
• [ ] Make the world adopt SenML