Backend

Install MQTT

sudo apt install mosquitto
sudo apt install mosquitto-clients

MQTT Broker

Before the server starts, run the following command to launch the MQTT broker:

mosquitto -c mosquitto.conf

Example

To publish messages from the command line, run the following command when the server is running:

mosquitto_pub -h localhost -t "topic" -m "1234"

In the above example, topic is the topic.

You can check the message is successfully received in the server log, e.g.,

received: 1234

You can also send random data continuously to simulate the real use case by running the command:

i=1; while true; do mosquitto_pub -h localhost -t "topic" -m "$RANDOM"; i=$((i+1)); sleep 1; done

MQTT Topics

• topic: data captured by the sensor is sent with this topic.

  {
    "time": "float",
    "activity": "bool",
    "y_acc": "float",
    "z_acc": "flaot",
    "y_correct": "bool",
    "z_correct": "bool"
  }

Run the App

Follow Install Docker Engine to install Docker Desktop.

To run the app, run:

docker-compose up

If you get the network mems-network declared as external, but could not be found error, run:

docker network create mems-network --subnet=192.168.1.0/24 --gateway=192.168.1.1

WebSocket

• WebSocket endpoint: http://localhost:8080/endpoint
  • http://localhost:3000 (e.g., React client) can connect to it.

WebSocket Topics

• /topic/time
  • type: float
• /topic/activity
  • type: bool
• /topic/y_acc
  • type: float
• /topic/z_acc
  • type: float
• /topic/y_correct
  • type: bool
• /topic/z_correct
  • type: bool

REST API

Add [/add]

Add new data

• Method: POST
• Body: data captured by sensor

  {
    "time": "float",
    "activity": "bool",
    "y_acc": "float",
    "z_acc": "flaot",
    "y_correct": "bool",
    "z_correct": "bool"
  }

• Response:

  {
    "data": {
      "id": "int",
      "datetime": "string",
      "dataJson": {
          "time": "float",
          "activity": "bool",
          "y_acc": "float",
          "z_acc": "flaot",
          "y_correct": "bool",
          "z_correct": "bool"
      }
    },
    "error": "string"
  }

Get [/get{?id}]

Get data of the specified id

• Method: GET
• Response:

  {
    "data": {
      "time": "float",
      "activity": "bool",
      "y_acc": "float",
      "z_acc": "flaot",
      "y_correct": "bool",
      "z_correct": "bool"
    },
    "error": "string"
  }

Delete [/delete{?id}]

Delete data of the specified id

• Method: GET
• Response:

  {
    "data": "int",
    "error": "string"
  }

Delete [/list{?offset}]

Get a list of data of with the specified offset

• Method: GET
• Response:

  {
    "data": [
      {
        "id": "int",
        "datetime": "string",
        "dataJson": {
          "time": "float",
          "activity": "bool",
          "y_acc": "float",
          "z_acc": "flaot",
          "y_correct": "bool",
          "z_correct": "bool"
        }
      }
    ],
    "error": "string"
  }