Home Assistant Kindle Screensaver

This tool can be used to display an overview of your Home Assistant instance on e.g. a jailbroken Kindle device.

If you're looking for a way to render a Lovelace view, see my newer project hass-lovelace-kindle-screensaver.

Demo

Features

It displays the current temperature and renders the history of the last 24hrs and the forecast of a weather component in a graph.

You might have to get used to the visualization, but the intention was to have the there values (history, now, forecast) in one single diagram, as this allows a comparison of the values. You can then ask yourself whether you can wear the same like yesterday or dress warmer or cooler.

Every minute, an image is generated from a website which is rendered by react. This image is converted into a format, which the Kindle e-ink screens can display. The device can then download the image and display it.

Usage

You may simple set up the sibbl/hass-kindle-screensaver docker container. It runs the server on port 5000 and can be configured using the following environment variables:

• HA_HOST=https://your-hass-instance.com
• HA_PORT=443
• HA_TOKEN=eyJ0... (you need to create this token in Home Assistant first)
• HA_ENTITY_TEMPERATURE=sensor.outdoor_temperature (state of this entity is displayed as current temperature)
• HA_ENTITY_WEATHER=weather.openweathermap (temperature and forecast attributes of this entity are used in the graph)
• HA_ENTITY_BATTERY=input_number.kindle_battery (optional input_number entity which is updated with the battery level, see details below)
• MOMENT_TIMEZONE=Europe/London (used for date/time calculations)
• MOMENT_LANGUAGE=en-US (used for date/time formatting)

You may also simply use the docker-compose.yml file inside this repository, configure everything in there and run docker-compose up.

Optional: battery level entity

I'm running my kindle without power supply and thus need to charge it about once a month. To have the battery level available in Home Assistant and let me notify about a low battery level, you can do the following.

1. Create a new input_number entity using the Home Assistant settings page.
2. Configure this entity's name in the HA_ENTITY_BATTERY environment variable.
3. Modify the following lines in the Kindle Online Screensaver plugin's bin/update.sh (absolute path on device should be /mnt/us/extensions/onlinescreensaver/bin/update.sh):

...
if [ 1 -eq $CONNECTED ]; then
-     if wget -q $IMAGE_URI -O $TMPFILE; then
+     batt=`powerd_test -s | awk -F: '/Battery Level/ {print substr($2, 0, length($2)-1) - 0}'`
+     if wget -q "$IMAGE_URI?battery=$batt" -O $TMPFILE; then
        mv $TMPFILE $SCREENSAVERFILE
        logger "Screen saver image updated"
...