Cayenne MQTT Python Library

The Cayenne MQTT Python Library provides functions to easily connect to the Cayenne IoT project builder <https://mydevices.com>_. With it you can send data to and receive data from Cayenne.

Requirements

• Python 2.7.9+ or 3.4+ <https://www.python.org/downloads/>_.
• This library <https://github.com/myDevicesIoT/Cayenne-MQTT-Python/archive/master.zip>_.
• Eclipse Paho MQTT Python client library <https://github.com/eclipse/paho.mqtt.python>_. This is installed as part of the Cayenne library installation.

Getting Started

Installation

This library can be installed using pip.

Python 2: ::

pip install cayenne-mqtt

Python 3: ::

pip3 install cayenne-mqtt

It can also be installed from the repository.

Python 2: ::

git clone https://github.com/myDevicesIoT/Cayenne-MQTT-Python cd Cayenne-MQTT-Python python setup.py install

Python 3: ::

git clone https://github.com/myDevicesIoT/Cayenne-MQTT-Python cd Cayenne-MQTT-Python python3 setup.py install

Cayenne Setup

1. Create your Cayenne account here <https://developers.mydevices.com/cayenne/features/>_.
2. Add a new device using the Bring Your Own Thing API selection.

Examples

Simple examples are available in the repository here: https://github.com/myDevicesIoT/Cayenne-MQTT-Python/tree/master/examples.

Below is an example of a simple client that publishes some sample data and receives data from Cayenne in a message callback. The Cayenne authentication variables must be modified with the authentication info you received when adding a new device in Cayenne: ::

import cayenne.client import time

Cayenne authentication info. This should be obtained from the Cayenne Dashboard.

MQTT_USERNAME = "MQTT_USERNAME" MQTT_PASSWORD = "MQTT_PASSWORD" MQTT_CLIENT_ID = "MQTT_CLIENT_ID"

The callback for when a message is received from Cayenne.

def on_message(message): print("message received: " + str(message)) # If there is an error processing the message return an error string, otherwise return nothing.

client = cayenne.client.CayenneMQTTClient() client.on_message = on_message client.begin(MQTT_USERNAME, MQTT_PASSWORD, MQTT_CLIENT_ID)

For a secure connection use port 8883 when calling client.begin:

client.begin(MQTT_USERNAME, MQTT_PASSWORD, MQTT_CLIENT_ID, port=8883)

i=0 timestamp = 0

while True: client.loop()

if (time.time() > timestamp + 10):
  client.celsiusWrite(1, i)
  client.luxWrite(2, i*10)
  client.hectoPascalWrite(3, i+800)
  timestamp = time.time()
  i = i+1

Documentation

For more detailed info about the Cayenne client API you can use pydoc. ::

pydoc cayenne.client

Additional Cayenne MQTT Libraries

Additional libraries are available for connecting to Cayenne with other languages. These can be found at https://github.com/myDevicesIoT.