- #WEATHER DISPLAY DOWNLOADS UPDATE#
- #WEATHER DISPLAY DOWNLOADS CODE#
- #WEATHER DISPLAY DOWNLOADS LICENSE#
- #WEATHER DISPLAY DOWNLOADS DOWNLOAD#
I haven’t tested how long the battery lasts with the current configuration, but I think it’s probably only a few days. If I were to look closely at the power daemon and rc.d, I probably could get it to turn off everything but the cron daemon and let cron turn on the WiFi as needed, but I think it’s not worth the effort as I don’t mind having it plugged in. I suppose I could use this and change the large image to “tomorrow,” but it’s easier just updating less frequently. Also, at some point in the evening, NOAA starts returning the forecast starting with the next day.
#WEATHER DISPLAY DOWNLOADS UPDATE#
I only update twice a day because the forecast doesn’t change that much with more frequent updates.
I then replaced the links to the icons, the temperatures, and the days of the week with strings to be replaced by the Python script.Ĭorrect, it uses wget over WiFi and uses USB power. I then inserted the icons into the “preprocess” file as “ ” and replaced what had been blank boxes with markup to use one of the icons. I initially created the SVG “preprocess” file and the icons using Inkscape, saved them as “Optimized SVG” to strip out various unneeded information, and finally edited them extensively by hand to simplify them.
#WEATHER DISPLAY DOWNLOADS LICENSE#
The main difference being, the MIT License requires attribution, while the CC0 license does not. The SVG “preprocess” file is with the MIT licensed code.
#WEATHER DISPLAY DOWNLOADS CODE#
I am releasing the icons under the CC0 Public Domain Dedication and the source code for the scripts under the MIT License. Either using pieces of these icons or from scratch, I created icons for the weather conditions there were no icons available for and for those where there were no public domain versions. To create the icons, I started off with public domain icons from the Noun Project. This initialization script was made easily accessible on power on of the Kindle using kite. In addition, the Kindle requires an initialization script to disable the framework and power daemons to prevent the screen from being overwritten and to prevent the Kindle from going into sleep mode, which would disable the WiFi as well as cron, preventing any forecast updates. On both the server and the Kindle, cron is used to execute the required scripts twice a day, with the server executing its scripts five minutes earlier than the Kindle to ensure a new image is ready. The Kindle portion of the system consists of a shell script that downloads the rendered image from the server, clears the screen twice to prevent ghosting, and then displays the image on the Kindle’s screen. Finally, it is copied to a public location on the web server.īefore running anything on the Kindle, one must first jailbreak it and obtain shell access this is left as an exercise for the reader. This SVG is then rendered as a PNG using rsvg-convert and converted to a grayscale, no transparency color space as required by the Kindle using pngcrush. This is accomplished by preprocessing a specially crafted SVG file to insert temperatures, forecast symbols, and days of the week. After parsing the data, the data then needs to be converted into an image.
#WEATHER DISPLAY DOWNLOADS DOWNLOAD#
The scripts first download and parse forecast data from NOAA via the National Digital Forecast Database XML/SOAP Service. The server side of the system uses shell and Python scripts to convert weather forecast data into an image for the Kindle. While the Kindle is capable of handling both parts, I already had a server, and utilizing it saved me the time and hassle of setting up a build environment for the Kindle. The server fetches and processes weather data to create an image, and the Kindle downloads and displays it. The system consists of two parts, one running on the wall-mounted Kindle and one running on a server. However, with the price of Amazon’s cheapest Kindle recently dropped to $69, I decided e-paper displays were finally cheap enough for me to pursue such a project: an e-paper based weather forecast display. Unfortunately, e-paper displays have always cost more than I was willing to spend on such a project. Ever since I first learned about electronic paper, I’ve thought it would be perfect to display some sort of regularly updated, but not real-time, data such as the current date, an agenda, or the weather forecast.
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