LBUtils

Background

This library is designed to install all of the common drivers, library code, and helper code used within modules at Leeds Beckett University. It is principally targeted at MicroPython on the Pico H/W micro-controllers: but compatibility is also maintained with CPython 3.10 where possible (or relevant).

Examples for how to use the library can be found in the 'examples' folder: or in the documentation. Otherwise the library is organised as follows

• drivers: Classes aimed at low-level support of I2C, SPI and other devices requiring board-level support.
• graphics: Classes providing support for drawing and text output on display devices.
• helpers: Functions and classes which help replace boiler-plate code for tasks such as setting up network access.
• pmod: Drivers and support for the Digilent peripheral modules.

Installation

A package of this library is provided on PyPi as lbutils. This can be installed with the normal Python tools, and should also install to boards running MicroPython under Thonny.

For manual installation, everything under the lbutils directory should be copied to the appropriate directory on the MicroPython board, usually /lib. The library, or individual drivers, can then be imported as normal: see the documentation for the examples for more detailed guidance on the use of the library. This code is also available in the lbutils/examples folder, or as the library lbutils.examples when the package is installed.

Contributions

Releases are pulled from the trunk, and development should be undertaken in branches to ensure that the code in trunk remains in working order. This library is principally a teaching library, so the Documentation should be at least as important as the 'code'. Where possible all algorithms and implementation techniques should also be explained as fully as possible, or at least linked to reference standards/implementations.

For consistency

• All code should also be in the format standardised by the Black library. This makes it easier to co-ordinate external code and documentation with the implementation documented here.

  Note: The 'future' style of black breaks the current (3.4) parser for MicroPython. Until this changes, only the 'current' style should be used.

• Code should pass ruff cleanly, with exceptions documented in the pyproject.toml file. Modern (Python > 3.10) conventions should be respected where possible: except where these conflict with the syntax accepted by MicroPython. In particular all libraries, functions and methods should have a type signature; dummy libraries should be used to support this where possible (see typing.py in the lbutils directory).

• Code is documented according to the NumPy documentation standard, and should be provided as standard Python docstrings. The docstrings are considered to be authoritative, and will be used to automatically document the class/method/etc.

• Docstrings should be in NumPy format, and should be checked by docformatter for correctness. Code documentation is generated by MkDocs, using the embedded docstrings in the code.

• All documentation, including documentation strings, should be in the [Markdown format accepted by MkDocs, and will be automatically rebuilt on commit. A basic check for documentation sanity can be done via

  docformatter --in-place --config ./pyproject.toml
  

• All documentation should be organised according to the Diátaxis framework: ideally with examples that do not require specific board set-ups. Where specific set-up are required, platforms such as WokWi should be used where possible to illustrate code and example set-ups.

Tools such as darglint might also be useful (and are installed with the default requirements.txt). However currently darglint has minimal support for the NumPy documentation standard, and so the output of darglint should be used with caution.

Where possible the above should be/is enforced by the use of a pre-commit hook for git. The script hook.sh in the bin directory is provided for this purpose, and can be installed as

cd .git/hooks; ln -s ../../bin/hook.sh pre-commit

from the project directory.

Known Implementations

• Raspberry Pi Pico H/W (MicroPython 3.4)
• CPython (3.10)