Submission - lirc572

[lirc572]

Submission Details

Type of Submission:

• 3 Pull requests
• Self-initiated open-source project

Link to open-source project:

https://github.com/lirc572/EPD75BHD

Additional information (optional):

This may be considered as a hardware project. It is an Arduino driver library for the Waveshare 7.5 inch 3-color e-paper display.

I bought the e-paper display some time ago and wanted to create a project with it. After I received the display, I tried searching for existing Arduino libraries for it, but then I found out that this is a relatively newly released module and I only found one library provided the producer, which does not satisfy my needs 😕 because:

• It is written in pure C and the it exports functions and structures that are tightly coupled, thus difficult to use in a large application
• To draw an image, it only supports converting the image to bitmap and put it in a C header file. This approach is very limited since it does not support drawing an image retrieved at runtime, and the microcontroller has enough flash memory to store only one full-screen image
• Its text drawing functions use a unique font format that is not compatible with Adafruit GFX fonts (the most popular font format for the Arduino framework), therefore it is difficult to port new fonts
• Its text drawing functions are very inflexible. It requires specifying a starting position for every text drawing operation, and formatted print is not supported, so it is necessary to call different functions to draw characters and numbers

To solve these problems, I decided to write a new driver library for the e-paper display, which leads to this project. About this library:

• It is completely written in C++. The whole library only exposes 2 classes and 2 stand-alone functions, all of them being straight-forward to use
• It supports reading images of PPM format from SD card. This format can be directly viewed on computers. I have also created a script to convert any color image to the supported PPM format using image dithering algorithm
• It uses Adafruit GFX fonts
• It has a formatted print function that is able to process format specifiers. It provides a similar experience as using C's printf in a computer termital

Please let me know if this project is acceptable! 😊😊😊

[chaitanyabaranwal]

Hey @lirc572, the project good to me! I really admire how you set upon creating your own library because the existing ones did not suit your purpose, and also made it open-source for everyone to access. The documentation is great too so good on that. Thanks for sharing your work and your OpenHack submission is now accepted!

Please visit https://openhack.nushackers.org/congrats and fill up the form so that we can capture your details for the prizes.

We hope you had fun working on the challenge and we hope you will continue making open-source contributions, even outside of the event! 😃