Smartmeter with SHRDZM device

I have a Smartmeter (Landis Gyr) and a little device (SHRDZM) that reads it using an IR sensor.
The SHRDZM can be connected in various ways. e.g. MQTT, modbus or simple http query of the devices REST address.

For reference in case others are wanting to do the same here is my http binding thing config with 3 channels (there are more in the JSON response).
The baseURL needs to be your devices REST address

UID: http:url:SmartMeterRESTAPI
label: SmartMeter REST API
thingTypeUID: http:url
configuration:
  authMode: BASIC
  ignoreSSLErrors: false
  baseURL: http://192.168.1.1/getLastData?user=F4CXXXXXX&password=1499999
  delay: 0
  stateMethod: GET
  refresh: 1
  commandMethod: GET
  contentType: application/json
  timeout: 3000
  bufferSize: 2048
channels:
  - id: SmartMeter_REST_2_7_0
    channelTypeUID: http:number
    label: Leistung Einspeisung
    description: ""
    configuration:
      mode: READONLY
      stateTransformation: JSONPATH:$['2.7.0']
      unit: W
  - id: SmartMeter_REST_1_7_0
    channelTypeUID: http:number
    label: Leistung Bezug
    description: null
    configuration:
      mode: READONLY
      stateTransformation: JSONPATH:$['1.7.0']
      unit: W
  - id: SmartMeter_REST_16_7_0
    channelTypeUID: http:number
    label: Leistung saldiert
    description: null
    configuration:
      mode: READONLY
      stateTransformation: JSONPATH:$['16.7.0']
      unit: W