Protocols Dataschemes

Protocols

This section describes the used protocols between the three core teams.

Sensors <-> Middleware

For the communication we use a JSON formatted string with the following format.

Current Version: 2

{
  "version":Integer,
  "timestamp": unix timestamp (milliseconds),
  "sensortype":"String",
  "values":[
    {
      "id":Integer,
      "value":Integer}
  ]
}

Valid values:

• version: Integers beginning with 1 and incremented by 1 with every change.
• timestamp: unix timestamp (milliseconds)
• sensor: Several valid types [unit]:
  • pressure [gram]
  • temperature [°C]
  • acceleration [unknown] possible:[deg/s]
  • gyroscope [unknown] possible:[deg]
  • microphone [unknown] possible:[dB]
  • distance [cm]
• values: Array of entries:
  • id: as an integer beginning with 0
  • value: as an integer

Example:

{
   "version":1,
   "timestamp": unix timestamp (milliseconds),
   "sensortype":"pressure",
   "values":[
      {
         "id":0,
         "value":1000
      },
      {
         "id":1,
         "value":1000
      }
   ]
}

Dataschemes

Message Queue Names

MQ1 Sensors <-> Middleware

Queues:

sg.q.sensor_values

• Durability: Durable
• Auto-Delete: False
• Arguments:

Exchanges:

sg.ex.sensor_values

• Type: Direct
• Durability: Durable
• Auto-Delete: False
• Internal: False
• Arguments:

Routing Keys:

sg.rk.sensor_values

• sg.ex.sensor_values ➙ sg.q.sensor_values

MQ2 Middleware <-> Database

Queues:

sg.q.ss

• Durability: Durable
• Auto-Delete: False
• Arguments:

Exchanges:

sg.ex.ss

• Type: Direct
• Durability: Durable
• Auto-Delete: False
• Internal: False
• Arguments:

Routing Keys:

sg.rk.ss

• sg.ex.ss ➙ sg.q.ss