Pololu Motor Control API

Installation

It is often useful to install python's virtual environments on your system. If using a Raspberry Pi, Beagle Bone, or any other Linux based credit card sized computer a virtual environment, can be useful, but is not necessary. On a larger computer it can help keep different project's packages separate from each other.

Installing a Virtual Environment

If you choose to use virtual environments for your working environment the following steps will install it for you. The docs are at: virtualenvwrapper.

• This will install the setuptools package needed to get easy_install.
  • $ sudo apt-get install python-setuptools
• Then use easy_install to install pip.
  • $ sudo easy_install pip
• Then use pip to install the virtual environment.
  • $ sudo pip install virtualenvwrapper
• Add the next two lines, using your favorite text editor, to the end of the .bashrc file in your home directory.
  • # Setup the Python virtual environment. source /usr/local/bin/virtualenvwrapper.sh
• Lastly resource the .bashrc file in your home directory.
  • $ source ~/.bashrc

Virtual Environment Hints

There are many commands that can be used with a virtual environment, for a full list see the link above. All commands below assume the virtual environment will be named pololu.

• To create a new environment type the below command outside of any virtual environments you may already have.
  • $ mkvirtualenv pololu
• To enter a virtual environment.
  • `$ workon pololu
• To exit a virtual environment.
  • $ deactivate
• To completely remove a virtual environment.
  • $ rmvirtualenv pololu

Installing pololu-motors with pip

Installing via pip is probably the simplest, but may not work on all platforms. If using a virtual environment be sure you are in the virtual environment before running the below command. Documentation for pip can be found at: pip.

• $ pip install pololu-motors

or directly from the git repository

• Check the version number at the end of the URL, it may have changed.
  • $ pip install git+https://github.com/cnobile2012/pololu-motors/t-v0.2.1

That's it, there is no more to do. The package will also install HTML API docs in <prefix>/share/doc/pololu_motors/index.html. Where <prefix> can be /usr, /usr/local, or ~/.virtualenvs/pololu.

Installing pololu-motors with setup.py

Installing this way is best if you get the code from a compressed file like a .zip or .tar.gz. This also would work from a clone of the git repository at: pololu-motors.

• Search on PyPi for pololu-motors then download the file.

or

• Clone the GitHub repository with
  • $ git clone https://github.com/cnobile2012/pololu-motors.git

After you have the package and expanded it in your work area, you may want to install it. Installing the package is not necessary if you just want to test it out, you can do that directly from the the git clone or the directory created by the downloaded tarball.

• This will install pololu-motors globally.
  • $ sudo python setup.py install

Building the Documentation

The API docs are generated with epydoc. If you want to build the docs yourself there are a few packages that need to be installed globally on your machine.

• Install the necessary packages.
  • $ sudo apt-get install python-epydoc epydoc-doc graphviz
• Build the docs.
  • $ make api-docs

Running unit tests.

Any good package should have unit tests. These tests give the developer a baseline of how the code should perform. To run the tests you will need a Qik 2s9v1, USB to serial adapter,
USB Cable A to Micro-B, breadboard and some jumper leads to connect it all together.

After all these items are installed properly you can run the tests. You can also connect a motor to M0. M1 is not tested at this time since most of the code is tested with M0.

There are two ways to run the unit tests, with the Makefile directly or with tox.

Using the Makefile

• $ make tests

Using tox

First you will need to install the tox subsystem then you will be able to run the tests.

• This command will install tox in a Python 3.x directory on your system, but this will not matter since it is run independently from your pololu-motor install.
  • $ sudo pip install tox
• Now run tox. It will run all the tests.
  • $ tox

Build Instructions

• The package is built with the make dist target in the Makefile.
• The version number of the package is ..and is only changed in theinclude.mk` file. You will not find the version defined anywhere else.

If you have any issue please contact me at: carl.nobile at gmail.com