kindle-calendar/dash/README.md

Low-power Kindle dashboard

Turns out old Kindle devices make great, energy efficient dashboards :-)

What this repo is

This repo only contains the code that runs on the Kindle. It periodically fetches an image to be displayed on the screen and suspends the device to RAM (which is very power efficient) until the next screen update.

This code does not render the dashboard itself. It's expected that what to display on the screen is rendered elsewhere and can be fetched via HTTP(s). This is both more power efficient and allows you to use any tool you like to produce the dashboard image.

In the current Voyage layered-clock setup, the Kindle only fetches a low-frequency kindlebg.png background. The clock face and hand patches are synced as local assets and re-drawn on-device once per minute without network access.

In my case I use a dashbling dashboard that I render into a PNG screenshot on a server. See here for information on how these PNGs should be produced, including some sample code.

Prerequisites

• A jailbroken Kindle, with Wi-Fi configured.
• An SSH server on the Kindle (via USBNetwork)
• Tested only on a Kindle 4 NT. Should work on other Kindle devices as well with minor modifications.

Installation

1. Download the latest release on your computer and extract it.
2. Modify local/fetch-dashboard.sh and optionally local/env.sh.
3. Copy the files to the Kindle, for example: rsync -vr ./ kindle:/mnt/us/dashboard.
4. Start dashboard with /mnt/us/dashboard/start.sh.
   Note that the device will go into suspend about 10-15 seconds after you start the dashboard.

Upgrading

If you're running kindle-dash already and want to update to the latest version follow the following steps.

1. Download the latest release on your computer and extract it.
2. Review the release notes. Some releases might require changes to files in local/.
3. Copy the files to the Kindle, excluding the local directory. For example: rsync -vur --exclude=local ./ kindle:/mnt/us/dashboard.
4. Modify files in /mnt/us/dashboard/local if applicable.
5. Start dashboard with /mnt/us/dashboard/start.sh.
   Note that the device will go into suspend about 10-15 seconds after you start the dashboard.

KUAL

If you're using KUAL you can use simple extension to start this Dashboard

1. Copy folder kindle-dash from KUAL folder to the kual extensions folder. (located in /mnt/us/extensions)

Debugging

For on-device debugging without suspending the Kindle, set DISABLE_SYSTEM_SUSPEND=true in local/env.sh. The dashboard loop will keep running and use a normal sleep between refreshes instead of writing to /sys/power/state.

If you're connected over SSH you can also run DEBUG=true ./start.sh to keep the process in the foreground with shell tracing enabled. If you're launching from KUAL, use Dashboard Debug On before a normal start to persistently disable suspend in local/env.sh, and Dashboard Debug Off when you want to restore the normal low-power behavior. Both actions stop the current dashboard process so the new setting takes effect on the next start. If you're connected over SSH and only want a one-off foreground session, you can still run /mnt/us/dashboard/start-debug.sh.

How this works

• This code periodically downloads a dashboard background image from an HTTP(s) endpoint.
• The interval can be configured in dist/local/env.sh using a cron expression.
• When layered clock assets are present, the Kindle re-renders the clock patch locally every minute.
• During the update intervals the device is suspended to RAM to save power.

Notes

• The releases contain a pre-compiled binary of the ht command-line HTTP client. This fully supports modern HTTPS crypto, wheras the built-in curl and wget commands don't (because they rely on a very old openssl library).
• For a detailed Kindle Voyage 5.13.6 jailbreak and deployment walkthrough, see docs/kindle-voyage-5.13.6-watchthis-zh.md.
• For a detailed same-device dashboard/SSH troubleshooting playbook based on the 2026-03-15 session, see docs/kindle-voyage-5.13.6-dual-ssh-playbook-zh.md.
• For the layered clock split and runtime model, see docs/layered-clock-plan.zh.md.

Credits

Thanks to davidhampgonsalves/life-dashboard for the inspiration!