Is there anything like this that can wake the Kindle up, get an image, and then sleep it again? I have an old Kindle that I want to show stuff on, but I don't want to keep it plugged in all the time.
kovac 15 minutes ago [-]
I work on e-paper displays. Are you looking for something built with a Kindle?
This project of mine is similar to what you described with a power down mode. The power down and wake up can be automated. I'm looking to build a small business around such projects. Not sure how viable it is.
I made some stuff of mine for that display too, but the easiest way is to just use TRMNL's firmware, as it supports autoupdates and a few other nice features.
The Kindle project is just because I have a few Kindles lying around, so I might as well use them!
bigiain 2 hours ago [-]
In case the author ever sees this...
If you have that battery level available off the Kindle, you can use it to turn a wifi "smart plug" on and off, to automatically top the charge up only when required.
(Or, more old-school, use a powerpoint timer set to only power up for a short time each day. I did this way back, when the place I worked decided they needed iPads stuck next to meeting room doors to stop arguments about who had it booked, but when they first installed them they left them plugged into the charger 24x7, and the batteries in them would puff up in 8-12 months and kill the iPads. Putting the charger in a timer so they only charged hour a day saved them about $6,000 a year in puffed up iPads.)
mtlynch 2 hours ago [-]
>I designed a backend API that collected the data in real-time data and exported it as a PNG image.
Does anyone know why in these Kindle modding dashboards, they always generate the dashbard image on an external server? Why isn't it possible to build all that functionality into an executable on the Kindle itself? You've got a Linux environment, so why can't you run all the logic locally?
kovac 2 hours ago [-]
I built this dashboard. The price curves and text are rendered locally from the microcontroller and painted pixel by pixel. Letters use raster fonts stored locally, price curves are generated on the fly. It can be done, it takes a bit of care. Mine only has ~400KB memory. It must be a lot easier on the Kindle, I think it runs Java even.
Most people today do not know how to program in the confines of 256MB of RAM and are not aware that languages other than javascript exist.
supportengineer 2 hours ago [-]
I expected the Kindle to do a few api calls and call ImageMagick but instead, in Cloudflare, it sets up a headless browser, and renders a web page to a PNG file on the server, and then only the final png image gets returned to the Kindle.
gitroom 3 hours ago [-]
lol i get weirdly obsessed with decimal places on stuff like this too - makes me laugh every time.
mahi_novice 4 hours ago [-]
Love this! Always fun to do stuff like this.
dmitrygr 5 hours ago [-]
4 significant figures on weather temperature is kind of funny to look at. Must be some very accurate forecasts
mobilemidget 5 hours ago [-]
I was just here to write the same thing :) imagine it being 0.01 degrees too warm or cold
alnwlsn 5 hours ago [-]
Reminds me of those times I work with temperature sensors which report in eighths of a degree. 3 decimal places to give less than one decimal place of precision. You can round, but somehow that doesn't feel right.
This project of mine is similar to what you described with a power down mode. The power down and wake up can be automated. I'm looking to build a small business around such projects. Not sure how viable it is.
https://www.asciimx.com/projects/e-reader/
https://usetrmnl.com
I made some stuff of mine for that display too, but the easiest way is to just use TRMNL's firmware, as it supports autoupdates and a few other nice features.
Here's mine:
https://www.stavros.io/posts/making-a-trmnl-device/
Plus this:
https://www.stavros.io/posts/making-the-timeframe/
And a few more things I never wrote about.
The Kindle project is just because I have a few Kindles lying around, so I might as well use them!
If you have that battery level available off the Kindle, you can use it to turn a wifi "smart plug" on and off, to automatically top the charge up only when required.
(Or, more old-school, use a powerpoint timer set to only power up for a short time each day. I did this way back, when the place I worked decided they needed iPads stuck next to meeting room doors to stop arguments about who had it booked, but when they first installed them they left them plugged into the charger 24x7, and the batteries in them would puff up in 8-12 months and kill the iPads. Putting the charger in a timer so they only charged hour a day saved them about $6,000 a year in puffed up iPads.)
Does anyone know why in these Kindle modding dashboards, they always generate the dashbard image on an external server? Why isn't it possible to build all that functionality into an executable on the Kindle itself? You've got a Linux environment, so why can't you run all the logic locally?
https://www.asciimx.com/projects/etlas/