LanguageLearner

Bilingual epaper news feed, designed to help me learn a new language. It's a simple epaper display using a Raspberry Pi Pico W (1st generation) and a 3d-printed stand. Is it helping? Non lo so, ma io provare.

Parts list

• Raspberry Pi Pico W with v1.28.0 Micropython firmware
• WeAct 4.2" B&W Epaper display (Waveshare Pico e-Paper 4.2 compatible) and included cable harness
• 3d-printed stand, this one was printed in PLA with supports
• M1.5x10mm machine screw and nut. I'll probably replace this with something slightly less janky when I print the next version of the stand, it's just to stop the screen rocking back in it's slot.

Operation

This script will:

• Connect to a preset WLAN
• Send a GET request to a preset URL (in this case an RSS feed)
• Trim the response down to a few chunks of text
• Send those chunks for translation by a different API (I'm using https://mymemory.translated.net/)
• Wrap the text for display on the screen
• Display on the screen
• Go to sleep for a few hours

Notes & Known Issues

• The original Pico W has limited RAM, which will restrict the URLs you can grab before it runs out of space and you get a memory allocation failure. I'm using a pretty simple RSS feed for this reason.
• The Waveshare driver is runnable as a demo to check wiring etc; it also has things like lines, grayscale, partial updates etc - https://www.waveshare.com/wiki/Pico-ePaper-4.2
• The Waveshare driver has only one font, which is about the right size for my use but only handles ASCII so Unicode/UTF16 doesn't render (see the grey boxes in the photos). It's fine for me, but if you want to use a language with lots other characters you'll need to cross that bridge yourself.

Instructions

For detailed instructions and default wiring, see the main LanguageLearner.py file. Assembly is straightforward.

Files are:

• LanguageLearner.py - The main script file
• wifi.json - Needs to be edited with your wifi connection details, and uploaded to the Pico at the same level as the main script
• /lib/epaper4_2.py - The Waveshare driver for talking to the display; should be inside the /lib folder that's at the same level as the main script. It's renamed from the one on Waveshare's Github because Micropython wouldn't import a file with a period in the title.