May 14th: Getting the screen to work
It was a long sitting and I got a TON done... but most of these are proof of concepts that will be later refined.
The firmware provided by the vendor was not compatible with any of the MCU's I had. Looking at the provided documentation and datasheets, the SSD1680 driver for 176x196 tri-color epaper displays seem to work with my 128x296 display. Some further search on the web lead me to this article, which confirms my theory.
By bodging Adafruit's SSD1680 CircuitPython library with their eink tutorial, I managed to get stuff to show, although the refresh rate is atrocious.
I followed Adafruit's custom font tutorial and bitmap image tutorial. A red square appeard at the top right of the bitmap image, I couldn't find a fix, so I added a white rectangle to cover it... it's a solution for now... The firmware is available at firmware/.
It was very time consuming entering coordinates, waiting for the display to refresh, and then repeat. I ended up making a local preview using PyGame, similar to HackaPet.
I then started cadding up a case for it, and it fits great after a few iterations! One of my goals is to make it as small and slim as possible, so tolerances are really important.
https://github.com/user-attachments/assets/4f26c620-6cda-4ded-9eeb-af5da3fae484
Total time spent: 8h
May 16th: De-soldering the connector
One of my goals is to make the badge as thin as possible. I want to be able to hang it on a t-shirt! After making sure the display works, I removed the JST connector as it is very tall. The 2x8 holes will be used to flash it instead. I absolutly suck at desoldering SMD components and had to go in with side cutters, but it works!
Total time spent: 1h
June 4th: Cad fixes and back plate
So Onshape assemblies are weird... and because I did it wrong the first time (I mated it to the wrong face) causing things to clip and dimensions to be incorrect. An attempt to try to fix it messed up the references between the sketches. It was easier to re-cad it from scratch. Ah... I love Onshape...
I also worked on the back plate to the name badge. I'm hoping a snap fit will be strong enough, but testing will be needed by printing it out!
Total time spent: 1hr