Cayenne MQTT Python Library

The Cayenne MQTT Python Library provides functions to easily connect to the Cayenne IoT project builder. With it you can send data to and receive data from Cayenne.

Requirements

• Python 2.7.9+ or 3.4+.
• This library.
• Eclipse Paho MQTT Python client library. This is installed as part of the Cayenne library installation.

Getting Started

Installation

This library can be installed using pip: :

pip install cayenne-mqtt

It can also be installed from the repository: :

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

Cayenne Setup

1. Create your Cayenne account at https://mydevices.com.
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.