About the project
Part of my prototyping/workshop efforts in my PhD project on sustainable technology design is on e-ink technology for mobile phones. Having tested the Yotaphone which features a second screen in monochromatic (black & white/greyscale) e-ink (e-paper) technology myself, the design brief and task I gave myself and workshop participants was "What if the low-energy e-ink display was the norm?"
Aim
Get an e-ink display to show pictures as we please... and if we are lucky also interact with it via touch functionality ;)
Is the interaction so much different compared to former LCD, LED, or OLED technology? How much of a sustainability gain can we expect from it, and how much of a required appropriation in interaction terms?
Result
After many many trials with an Arduino Uno, with PlugIns of Paper Pi type, and finally plain (re)use of Raspberry Pi code snippets, it works to show 7-colour picture content (+ custom text, drawings or similar) as one pleases.
Background
Though I had gotten in touch with e-ink display technology back in 2008 (student project with Pricer AB, Sweden), and followed along with the technology's development expecting somewhen colour e-ink to appear, I managed to miss the fact by 2 years! ;)
Ordered the shown display (from China of course one has to) in 2021 and trialed my way...
Finance
The display costs around 60$, plus postage costs, ordered on Alibaba (from China).
Collaboration
- Thanks to my colleague Heidi for being so patient with me learning to use and misuse Arduino... I wonder whether I ever will find the time to really dive into 'Libraries' ;-)
- Thanks to the tutorial creators around Paper Pi, and Raspberry Pi/Arduino with e-paper!
- And thanks to student Dusan who participated right from the 'RGB' heureka moment, when finally images turned up in the 7 colours the display provides.
- Possibly, there will be collaboration via Bitraf (Makerspace in Oslo) with a maker who calculates/creates high-resolution pretending pictures but based on just 3-4 colours! That means such pictures are very low on memory/size AND are still pleasing to the human eye :)
Equipment
7-colour e-ink display, Arduino Uno, wiring, code snippets used and tutorials from Arduino-folks
(first and foremost: https://www.waveshare.com/wiki/5.65inch_e-Paper_Module_(F)#Hardware_connection; then also e.g. https://learn.adafruit.com/preparing-graphics-for-e-ink-displays?view=all)
7-colour e-ink display, Raspberry Pi, wiring/cable, keyboard, mouse, monitor (at university workplace/the lab), code snippets used from RaspberryPi-folks
(first and foremost: https://dronebotworkshop.com/epaper/, particular on PaperPi: https://dronebotworkshop.com/epaper/#PaperPi_Hardware_Requirements, and finally used: https://dronebotworkshop.com/epaper/#e-Paper_coding_with_Python where I replaced a '1' in code line ... image = Image.new(mode='1' ... with 'RGB' to do the (colour) trick.)
--> now get own content on the screen like this: Make a .bmp file for e-paper (https://www.waveshare.com/wiki/E-Paper_Floyd-Steinberg) 
Update 2023
The results from the participatory work with design researcher colleagues and electronics experts up to the colour e-ink display are featured in this short paper:
https://dl.designresearchsociety.org/iasdr/iasdr2023/shortpapers/62
Envisioning sustainable smartphone alternatives: a plurishop approach
Ines Petra Junge, University of Oslo, Norway
Alma Leora Culén, University of Oslo, Norway
Kim Øyhus (the possible collaborating maker from Bitraf) has furthered (his) image dithering technique to work with such 7-colour e-ink screens, see the website: Photo-epaper.