pycayennelpp 2.0.0

Encoder and Decoder for CayenneLLP

PyCayenneLPP

A Cayenne Low Power Payload (CayenneLPP) decoder and encoder written in Python.

PyCayenneLPP offers a concise interface with proper encoding and decoding functionality for the CayenneLPP format suporting many sensor types. Further, the project aims for overall high code quality and good test coverage.

See also myDevicesIoT/CayenneLPP for more information on the format and a reference implementation in C++.

The project is under active development. Releases will be published on the fly as soon as a certain number of new features and fixes have been made.

Supported Data Types

The following table lists the currently supported data types with the LPP code (which equals IPSO code - 3200), data size in bytes, and data dimensions.

Type Name	LPP	Size	Dim
Digital Input	0	1	1
Digital Output	1	1	1
Analog Input	2	2	1
Analog Output	3	2	1
Generic	100	4	1
Illuminance	101	2	1
Presence	102	1	1
Temperature	103	2	1
Humidity	104	1	1
Accelerometer	113	6	3
Barometer	115	2	1
Voltage	116	2	1
Load	122	3	1
Unix Time	133	4	1
Gyrometer	134	6	3
GPS Location	136	9	3

Getting Started

PyCayenneLPP does not have any external dependencies and only uses builtin functions and types of Python 3. It is compatible with all the latest and officially supported Python versions 3.6 and above, though even Python 3.4 will do.

Since PyCayenneLPP 1.2.0 MicroPython is officially supported, and published as a separate package under micropython-pycayennelpp.

Python 3 Prerequisites

The PyCayenneLPP package is available via PyPi using pip. To install it run:

pip3 install pycayennelpp

MicroPython Prerequisites

Using MicroPythons upip module PyCayenneLPP can be installed as follows within MicroPython:

import upip
upip.install("micropython-pycayennelpp")

Or alternatively run with in a shell:

micropython -m upip install micropython-pycayennelpp

Usage Examples

The following show how to utilise PyCayenneLPP in your own application to encode and decode data into and from CayenneLPP. The code snippets work with standard Python 3 as well as MicroPython, assuming you have installed the PyCayenneLPP package as shown above.

Encoding

from cayennelpp import LppFrame


# create empty frame
frame = LppFrame()
# add some sensor data
frame.add_temperature(0, -1.2)
frame.add_humidity(6, 34.5)
# get byte buffer in CayenneLPP format
buffer = bytes(frame)

Decoding

from cayennelpp import LppFrame


# byte buffer in CayenneLPP format with 1 data item
# i.e. on channel 1, with a temperature of 25.5C
buffer = bytearray([0x01, 0x67, 0x00, 0xff])
# create frame from bytes
frame = LppFrame().from_bytes(buffer)
# print the frame and its data
print(frame)

Contributing

Contributing to a free open source software project can take place in many different ways. Feel free to open issues and create pull requests to help improving this project. Each pull request has to pass some automatic tests and checks run by Travis-CI before being merged into the master branch.

Please take note of the contributing guidelines and the Code of Conduct.

License

This is a free open source software project published under the MIT License.