partial refresh | adafruit | Page 1

wanton hare Oct 3, 2021, 4:01 PM

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trying to have a menu type thing, and waiting for the full display refresh is kinda slow

fallow owl Oct 3, 2021, 4:30 PM

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I think some of the EPDs have that capability, but I recall some ladyada videos where she was testing it out and it had minor pros and cons, didn't seem worth doing

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I don't think these EPDs are really designed to be interactive... the refresh cycles are supposed to have delays of many seconds between them to protect the display

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though there is one video demonstrating it https://blog.adafruit.com/2020/12/07/new-video-eink-partial-updates-eink-thinkink/

wanton hare Oct 3, 2021, 5:04 PM

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yeah I was under the impression that the greyscale ones are also partial-update-capable

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I've done some interactive stuff on a hacked Kindle, but the magtag is just an easier platform 🙂

wanton hare Oct 3, 2021, 6:59 PM

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Ok, got it down to one menu level instead of nested, and using the neopixels for faster response to input

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Maybe I'll look at the Arduino code to see what it says, because partial updates mean you don't need to do the whole cycle on the full display, but in any case my project works now 😁

wanton hare Oct 3, 2021, 8:22 PM

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Oh interesting, it looks like there should be windowed update support of some kind based on looking at the source code...

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Maybe have to do something with the groups?

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Oh might just be partially uploading instead of pushing the entire framebuffer

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Might have to wire up my own display commands

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Hmm now I'm seeing "don't refresh with less than 180 seconds in between" which is hard especially during debugging, my program usually doesn't run 180 seconds if I have a bug. Hopefully that's just a rule of thumb - there are also clock projects on the learning system which don't follow that

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Looks like command 90h sets up a partial window, 91h enters partial mode, 92h exits partial mode

#partial refresh