iot-plot

Remote plotting library for resource constrained devices. Uses MQTT for communication. plotclient is compatible with MicroPython, enabling small microcontrollers to create high quality plots of measurement data.

Installation

pip install iot-plot

This also installs matplotlib, if not installed already. iot-plot requires Python 3.

To upgrade to a new version, run

pip install iot-plot --upgrade

Depending on your python installation, you may also need to install or configure a backend for the plotting to work. See instructions at the end of this document.

Usage

Start the server on a host (e.g. laptop):

$ plotserver

then create plots using iot_plot/plotclient.py. Run

$ plotclient

(and check the code) to generate

In a real application you would use the PlotClient object on the microcontroller.

Backend

The plotserver requires a properly installed backend for all features to work, e.g. generating pdf output. See https://matplotlib.org/tutorials/introductory/usage.html#what-is-a-backend for more information.

Error from plotserver on OSX:

On OSX, if you get an error similar to this:

**RuntimeError**: Python is not installed as a framework.
The Mac OS X backend will not be able to function correctly if
Python is not installed as a framework. See the Python
documentation for more information on installing Python
as a framework on Mac OS X. Please either reinstall Python
as a framework, or try one of the other backends.

Try the following solution (found on stackoverflow.com):

Problem Cause In mac os image rendering back end of matplotlib (what-is-a-backend to render using the API of Cocoa by default). There is Qt4Agg and GTKAgg and as a back-end is not the default. Set the back end of macosx that is differ compare with other windows or linux os.

I resolve this issue following ways:

• I assume you have installed the pip matplotlib, there is a directory in you root called ~/.matplotlib.
• Create a file ~/.matplotlib/matplotlibrc there and add the following code: backend: TkAgg