/mqtt-simulator

Easy-to-configure MQTT simulator written in Python to simulate the sending of JSON objects from sensors or devices to a broker.

Primary LanguagePythonMIT LicenseMIT

MQTT Simulator

Easy-to-configure MQTT simulator written in Python 3 to simulate the sending of JSON objects from sensors or devices to a broker.

Features • Getting Started • Configuration • Authors

Simulator Running

Features

  • Small and easy-to-configure simulator for publishing data to a broker
  • Configuration from a single JSON file
  • Connection on pre-defined fixed topics
  • Connection on multiple topics that have a variable id or items at the end
  • Random variation of data generated according to configuration parameters

Getting Started

Prerequisites

Installing Dependencies

To install all dependencies with a virtual environment:

python3 -m venv venv
source venv/bin/activate
pip3 install -r requirements.txt

Running

The default simulator settings can be changed in the config/settings.json file.

python3 mqtt-simulator/main.py

Runs the simulator according to the settings file.
The terminal will show the simulator event log.

Optionally, you can pass a flag with the path to settings file:

python3 mqtt-simulator/main.py -f <path/settings.json>

Configuration

  • The config/settings.json file has three main configuration parameters:

    {
    "BROKER_URL": "mqtt.eclipse.org",
    "BROKER_PORT": 1883,
    "TOPICS": [
        ...
    ]
}
    Key Type Description Required
    BROKER_URL string The broker URL where the data will be published yes
    BROKER_PORT number The port used by the broker yes
    TOPICS array<Objects> Specification of topics and how they will be published yes

  • The key TOPICS has a array of objects where each one has the format:

    {
    "TYPE": "multiple",
    "PREFIX": "temperature",
    "RANGE_START": 1,
    "RANGE_END": 2,
    "TIME_INTERVAL": 25,
    "RETAIN_PROBABILITY": 0.5,
    "DATA": [
        ...
    ]
}
    Key Type Description Required
    TYPE string It can be "single", "multiple" or "list" yes
    PREFIX string Prefix of the topic URL, depending on the TYPE it can be concatenated to /<id> or /<item> yes
    LIST array<any> When the TYPE is "list" the topic prefix will be concatenated with /<item> for each item in the array if TYPE is "list"
    RANGE_START number When the TYPE is "multiple" the topic prefix will be concatenated with /<id> where RANGE_START will be the first number if TYPE is "multiple"
    RANGE_END number When the TYPE is "multiple" the topic prefix will be concatenated with /<id> where RANGE_END will be the last number if TYPE is "multiple"
    TIME_INTERVAL number Time interval in seconds between submissions towards the topic yes
    RETAIN_PROBABILITY number Number between 0 and 1 for the probability of the previous data being retained and sent again yes
    DATA array<Objects> Specification of the data that will form the JSON to be sent in the topic yes

  • The key DATA inside TOPICS has a array of objects where each one has the format:

    {
    "NAME": "temperature",
    "TYPE": "float",
    "MIN_VALUE": 30,
    "MAX_VALUE": 40,
    "MAX_STEP": 0.2
}
    Key Type Description Required
    NAME string JSON property name to be sent yes
    TYPE string It can be "int", "float" or "bool" yes
    MIN_VALUE number Minimum value that the property can assume If TYPE is different from "bool"
    MAX_VALUE number Maximum value that the property can assume If TYPE is different from "bool"
    MAX_STEP number Maximum change that can be applied to the property from a published data to the next If TYPE is different from "bool"

Authors

DamascenoRafael  Maasouza