Install the software¶
See also How to prepare a Raspberry Pi Zero to drive the plotter, which gives step-by-step directions specifically for using a Pi Zero as the plotter engine.
brachiograph.py requires a few additional components. It’s recommended to use a virtualenv for the Python
packages; either way, make sure you are in a Python 3 environment.
For convenience (optional but recommended)¶
Create and activate a Python virtual environment to work in:
python3 -m venv env source env/bin/activate
If not already installed, or if you’re not using a virtual environment:
sudo apt-get install python3-pip
This version of pip needs to be invoked with
pip3, so if you are not using a Python virtual environment,
pip3 in the examples below.
PIGPIO is an excellent library that provides hardware control of the Pi’s GPIO pins - important for accurate timing of pulses. It comes with a Python interface to the lower-level code.
sudo apt-get install pigpiod pip install pigpio # use pip3 if not using a virtual environment
Pillow is a Python imaging library. You’ll need it to process convert bitmap images to vectors, but it’s not required to drive the plotter.
Install the required system libraries (listed at https://www.piwheels.org/project/Pillow/), followed by Pillow itself:
sudo apt install libwebp6 libtiff5 libjbig0 liblcms2-2 libwebpmux3 libopenjp2-7 libzstd1 libwebpdemux2 libjpeg-dev pip install pillow # use pip3 if not using a virtual environment
Numpy is a Python mathematics library.
Install the required system libraries (listed at https://www.piwheels.org/project/numpy/), followed by Numpy itself:
sudo apt install libatlas3-base libgfortran5 pip install numpy # use pip3 if not using a virtual environment
If not already installed:
sudo apt-get install git
Other Python packages¶
Use pip to install Python 3 versions of:
tqdm# for the progress indicator while drawing
readchar# to allow the
BrachioGraph.drive()methods to accept user input
pip install tqdm readchar # use pip3 if not using a virtual environment
Clone the BrachioGraph repository¶
If you haven’t already done so, clone the
git clone firstname.lastname@example.org:evildmp/BrachioGraph.git
or, if you need to use HTTPS instead:
git clone https://github.com/evildmp/BrachioGraph.git