I've setup multiple "Photo frames" with Raspberry Pi zero connected with screen of different size, which fetches the photos stored on local hard drive hosted with Lomorage running on Raspberry Pi 4. Check it out, https://www.reddit.com/r/raspberry_pi/comments/fj3li8/digtal...
I built a picture frame with a greyscale e-paper that runs on battery for years
81–85 of 85 posts
Re: I built a picture frame with a greyscale e-paper that runs on battery for years
#82Earlier quoted context omitted.
> E-ink is not the most suitable thing for it in its current form. What would you say is?
As I wrote above, from technical side, it is the great cost of i creasing gray depth
I agree that the poor contrast etc of EPDs hurt them, including in this area. I'm questioning what you think are better alternatives for this use; I don't think there are any that don't have flaws worth weighing.
Re: I built a picture frame with a greyscale e-paper that runs on battery for years
#83Looks pretty neat.
I only wish it were USB-C. If the battery really lasts years, I won't have any micro-USB laying around when I next need to charge it.
I only had two of those cables left, and had to throw one out this week since it stopped working.
Re: I built a picture frame with a greyscale e-paper that runs on battery for years
#84I worked on a number of digital photo frames, including on ones like that. E-ink is not the most suitable thing for it in its current form. First, large size EPD cost an arm, and a leg, and custom one costs even more. Second, there are no 8 bit EPD controllers as of now a mortal can buy, which means grays look very bad. Third, there are inherent physical limitations which make increasing gray resolution of EPDs quite…
Second, there are no 8 bit EPD controllers as of now a mortal can buy, which means grays look very bad. Third, there are inherent physical limitations which make increasing gray resolution of EPDs quite hard. The precision you want, the slower would the refresh rate be. For a digital picture frame, refresh rate isn't that important. In fact, a "gradual shading" on refresh might even make for a neat transition effect[…
EPDs are highly, highly nonlinear in their driving response.
It for a good reason full info behind making LUTs for driving EPD screens is kept as high secret.
Re: I built a picture frame with a greyscale e-paper that runs on battery for years
#85I had this idea years ago! I'm glad someone finally did it. One thought. From a philosophical point of view, I would want this to be something that "lasts forever". So it would be nice if it were solar powered and ran off of an SD card rather than being web-based. Just an opinion from an HN extremist - take it in context. Still, it's scratching an itch for me. Your website is down so I didn't see how much it costs bu…
I published this yesterday, in case you are interested: https://news.ycombinator.com/item?id=25461853