Sensor-data-bridge

Project LoraLuftdatenForwarder
File:Nopicture.jpg
LoRaWAN forwarder for particulate matter data
Status	In progress
Contact	bertrik
Last Update	2021-03-23

What is this

This is a Java application that sends airborne particulate matter measurement data from TheThingsNetwork and forwards it to sensor.community (formerly Luftdaten).

It is used in combination with my LoraWanDustSensor: the sensor sends measurement data to TheThingsNetwork, this application picks up the data from TheThingsNetwork and forwards it to sensor.community and to opensensemap.org.

Next steps:

• add support for NB-IOT modem with t-mobile backend, see my Sim7020 project

Requirements

You need the following:

• a server that is always on and connected to the internet, can be Linux or Windows
• a Java installation (JDK to compile), at least version 8
• some configuration on TheThingsNetwork side
• some configuration of my application (YAML file)

Compilation

To compile the software:

• clone the software from my github archive

 git clone https://github.com/bertrik/LoraLuftdatenForwarder.git

• enter the LoraLuftdatenForwarder/gradle directory

 cd LoraLuftdatenForwarder/gradle

• run the gradle script to build the software:

 ./gradlew assemble

• the application zip & tar is now available in LoraLuftdatenForwarder/LoraLuftdatenForwarder/build/distributions

To update to the latest version:

• Update software from github archive:

 git pull

• perform the last two steps above again

Installation

Unzip the distribution file somewhere on your system. I put it in my home directory, for example

 cd
 tar xvf code/LoraLuftdatenForwarder/LoraLuftdatenForwarder/build/distributions/LoraLuftdatenForwarder.tar

Configuration

Node configuration

The particulate matter measurement device needs to send data in the Cayenne format. I used the following conventions:

• PM10 is encoded as analog value on channel 1
• PM2.5 is encoded as analog value on channel 2
• PM1.0 is encoded as analog value on channel 0 (optional)
• Temperature is encoded using standard Cayenne encoding (optional)
• Humidity is encoded using standard Cayenne encoding (optional)
• Barometric pressure is encoded using standard Cayenne encoding (optional)

TheThingsNetwork

TTN API key rights

You need to define an 'application' on TheTheThingsNetwork.

• Go the TTN console: https://console.cloud.thethings.network/ and log in
• You need an 'application', create a new one, or use an existing one
• Within the application you need a 'device', so create a new one, or use an existing one:
  • Use OTAA
  • Enter the device EUI as displayed on the display
  • Use the application keys as specified in my LoraWanDustSensor page
• You need an API key
  • Create this on the TTN console, grant individual rights as shown in the screenshot
  • NOTE: you have only one chance to copy this key somewhere, so copy/paste it locally to a text file or something

LoraLuftdatenForwarder configuration

To configure the application:

• Start the application without a configuration file, this will create a default template, stop the application again

 cd LoraLuftdatenForwarder
 bin/LoraLuftdatenForwarder
 (ctrl-C)

• Edit the loraluftdatenforwarder.yaml file, example:

---
ttn:
  mqtt_url_v2: "tcp://eu.thethings.network"
  mqtt_url_v3: "tcp://eu1.cloud.thethings.network"
  identity_server_url: "https://eu1.cloud.thethings.network"
  identity_server_timeout: 20
  apps:
  - name: "particulatematter"
    version: "V3"
    key: "NNSXS......."
    encoding: "CAYENNE"
luftdaten:
  url: "https://api.sensor.community"
  timeout: 20
opensense:
  url: "https://api.opensensemap.org"
  timeout: 20
  ids:
    "0ttn-deveui-here": "put-opensense-boxid-here"
    "0004A30B001E00BE": "5eca4a0fd0545b001c0e5d46"

So:

• enter the name of your application
• enter the TTN API key you saved earlier
• other defaults are probably OK

Sensor.community

TODO

• Go to https://devices.sensor.community/ and log in
• Register a node with id 'TTN-<device-EUI-as-shown-on-display>'
• Register it with the proper configuration, e.g. SDS011 with BME280

Opensensemap

TODO

• Create a node with the proper configuration
• Copy the opensensenmap 'box id'
• Add an attribute in the TTN console:
  • Go to the TTN console, General settings of the device
  • Add attribute, name = 'opensense-id', value = box id that you just copied
• The boxid should be picked up automatically by the forwarder, within an hour