Kindle Smart Dashboard DIY Guide

Turn an old Kindle into a smart dashboard by jailbreaking it, configuring network settings, disabling the UI, and displaying a grayscale image fetched from a Cloudflare Workers API server.

Turning Your Old Kindle into a Smart Dashboard

Intro Hook

• Ever wondered what to do with that old Kindle lying around?
• How about turning it into a smart dashboard?

Jailbreaking the Kindle

• Easy process with a user-friendly guide at kindlemodding.org.
• Main Steps:
  1. Identify your Kindle model.
  2. Install WinterBreak.
  3. Setup a hotfix.
  4. Install Kindle Unified App Launcher and a package installer.
  5. Enable SSH using USBNet.
• Troubleshooting: KindModding Discord community.

Network Configuration

• USBNet package might not work; try USBNetLite.
• Two connection modes:
  1. RNDIS/Ethernet gadget.
  2. SSH over network using the IP address.
• Steps to enable SSH:
  1. Enable USBNet from the KUAL Menu.
  2. Set the IP address manually (e.g., 192.168.15.201).
  3. SSH using the IP address.
  4. Enter the password from the /etc/config file.

Creating the Dashboard

• Challenge: Kindle OS is a stripped-down Linux version with no package manager.
• Approach: Disable the framework and display a PNG image periodically in full-screen mode.
• Key Steps:
  1. Stop Kindle UI frameworks and screensavers.
  2. Check internet accessibility.
  3. Fetch the PNG image from the server using curl.
  4. Display it fullscreen using the eips command.
• Important: Images need to be in 8-bit Grayscale and match the Kindle's display resolution (find using eips -i).

API Server in the Cloud (Cloudflare Workers)

• Using Cloudflare Workers, Hono JS, Cloudflare KV, Bun, and TypeScript.
• Data Sources:
  • Weather: Pirate Weather API (via Merry Sky).
  • Public Transport: VBB Berlin API.
  • School Timetable: Hardcoded data, future KV/D1 integration possible.

Image Processing

• Required: Render webpage, take a screenshot, convert to 8-bit Grayscale.
• Tools: Cloudflare Browser rendering (Puppeteer), cf-wasm.
• Steps:
  1. Capture a screenshot using Puppeteer.
  2. Convert the image to grayscale using cf-wasm.
• Code Snippet (Grayscale Conversion):

    const gray = Math.round(0.299 * r + 0.587 * g + 0.114 * b);
    grayscaleData[i / 4] == gray;
  

Final Thoughts

• Fun project with a practical outcome.
• Kindle battery lasts about two weeks.
• Great hacking device; cheap on eBay.
• Code available on GitHub:
  • Kindle Dash Client
  • [School dashboard backend](https://github.com/samkhawase/school-dash-backend