Sensor Station

Sensor Station gathers data via MQTT from any number of publishers, which are typically battery powered, wireless sensors spread around a certain location.

Overview

MQTT is the key

MQTT Broker

• Run MQTT broker, e.g. mosquitto

• Base topic "ss//data/"

Example: ss/00:95:fb:3f:34:95/data/tempc 25.00

Web Sockets

We sockets or HTTP/2 will be used to send data to and from the IOTe device (otto) in our case.

Subscribe to Topics

• announce/station - announces stations that control or collect

• announce/hub - announces hubs, typ

• data/tempc/ - data can have option /index at the end

• data/humidity

• control/relay/idx - control can have option /index at the end

REST API

• GET /api/config

• PUT /api/config data => { config: id, ... }

• GET /api/data

• GET /api/stations

Station Manager

• Collection of stations
• Stations can age out

Stations

• ID (name, IP and mac address)
• Capabilities
  • sensors
  • relay

Data

Data can be optimized and we expect we will want to optimize different data for all kinds of reasons and we won't preclude that from happening, we'll give applications the flexibility to handle data elements as they see fit (can optimize).

We will take an memory expensive approach, every data point can be handled on it's own. The data structure will be:

struct Data
    Source ID
    Type
    Timestamp
    Value

User Interface

Build

1. Install Go
2. go get ./...
3. cd ss; go build

That should leave the execuable 'sensors' in the 'sensors' directory as so:

./station/sensors/sensors

Deploy

1. Install and run an MQTT broker on the sensors host (e.g. mosquitto).

2. Start the sensors program ensuring the sensor station has connected to a wifi network.

3. Put batteries in sensors and let the network build itself.

Testing

Fake Websocket Data

% ./ss -fake-ws

% ./ss -help

This will open the following URL for the fake websocket data:

http://localhost:8011/ws

Replace localhost with a hostname or IP if needed. Have the websocket connect to the URL and start spitting out fake data formatted like this:

{"year":2020,"month":12,"day":10,"hour":20,"minute":48,"second":8,"action":"setTime"}
{"K":"tempf","V":88}
{"K":"soil","V":0.49}
{"K":"light","V":0.62}
{"K":"humid","V":0.12}

Adding Automated Builds

Automated builds will be using Github events.