ECE434 Project - BBIO in Python Project

Revision as of 15:07, 12 November 2020 by Morsee (talk | contribs) (Executive Summary)
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thumb‎ Embedded Linux Class by Mark A. Yoder

Team members: Eric Morse Joshua Key

Grading Template

I'm using the following template to grade. Each slot is 10 points. 0 = Missing, 5=OK, 10=Wow!

09 Executive Summary
09 Packaging
09 Installation Instructions 
09 User Instructions
09 Highlights
09 Theory of Operation
09 Work Breakdown
09 Future Work/Conclusions
09 Demo/Poster
00 Late
Comments: Have a good day.

Score:  90/100

(Inline Comment)

Executive Summary

Picture that summarizes the project.

BBIO are a group of library files for GPIOD that are written in C that uses Python wrappers to run it in Python. Our project is to rewrite the Python to be fully in Python rather than using wrappers.

What works: The GPIO, UART, and ADC capabilities will now run the same way they normally would, except the Python does not use a Python wrapper.

What isn't working. The programs have only been tested on the BeagleBone Black with kernel 4.19. The BBIO programs may not function correctly on other kernels or BeagleBones.

Conclusion: The BBIO library no longer requires a Python wrapper as all of the functions interact with the BeagleBone directly from Python.

Packaging (N/A)

If you have hardware, consider Small Build, Big Execuition for ideas on the final packaging.

Installation Instructions

Give step by step instructions on how to install your project.

  • Include your github path as a link like this to the read-only git site:
  • Be sure your is includes an up-to-date and clear description of your project so that someone who comes across you git repository can quickly learn what you did and how they can reproduce it.
  • (N/A) Include a Makefile for your code if using C.
  • (N/A) Include any additional packages installed via apt. Include and files.
  • (N/A) Include kernel mods.
  • (N/A) If there is extra hardware needed, include links to where it can be obtained.

User Instructions

The programmer has to import the library into the code that they write and call the gpiod functions from that library.


We created a full drop-in replacement of gpiod's pywrapper in C to a full python implement of gpiod for python programmers. It has full gpiod functionality with gpio pin event detection and setting outputs on gpio pins. It supports setting directions during setup. It also supports setting up multiple gpio pins at the same time, which is how gpiod differs from regular gpio. It has full support for UART functionality as well as ADC conversions.

Theory of Operation

The library is a drop-in replacement of the py-wrapper version of BBIO gpiod. A programmer would import the library files into the code they write and call the functions.

.setup() to setup a gpio pin.

.output() to configure the output of a gpio pin that has been setup already.

.add_event_detect() to detect a change in the value of a gpio pin, and go to a callback function when it changes.

.cleanup() to close all memory allocations and remove all pins.

Work Breakdown

Joshua Key and Eric Morse did pair-programming.

We worked the entire project and all modules together.

We completed all GPIO functionality of GPIOD, including event detection.

We completed all UART functionality of GPIOD.

We also completed all PinMux and ADC (Analog to Digital Conversion) of GPIOD.

Mark Yoder did initial work on, and worked most of it, except event detection.

Future Work

The columns are being changed in an update to BBIO, which will mean that the columns of our table will need to be changed to reflect that. The code should work fine, but maintenance of the code will need to happen if it does not work under any new update.


In the near future, there will be a new image for the 4.19 Black kernel that will switch the Consumer and the Name for gpioinfo. This will remove an error that we had to work around, which will require an update to implement. Additional functionality will need to be implemented to both the C and the Python library.

thumb‎ Embedded Linux Class by Mark A. Yoder