How I turned an old Kindle into a slow-refresh security camera monitor

Now that I've finally jailbroken my Kindle, I can't stop thinking of things to do with it. I'd messed around with making it display various things, and I wondered if I could make it do something genuinely useful and display the feed from my video doorbell.

I've used my Kindle to do some strange things

I got it working as a portable monitor

I'd always held off from jailbreaking my ancient Kindle because I loved using it too much and didn't want to brick it by mistake. When Amazon announced that it would no longer support older Kindle models like mine, however, there was no longer anything to hold me back.

Once the Kindle was jailbroken, I realized that there was so much more I could do with it. I've managed to turn my fingers into a page turner using my Apple Watch, I've turned the Kindle into an E-Ink dashboard for Home Assistant when I'm not using it for reading, and I've even made it work as a slow-refresh portable monitor for my Mac.

While some of the things I've tried out on my Kindle aren't the most useful features I've ever set up, they were fun to figure out. However, I wanted to try to make my Kindle do something genuinely useful.

I wanted a quick way to see who was at the door

When I'm reading a book, I don't always want to be disturbed

Sometimes when I'm reading my Kindle, the doorbell will ring. I'll get out of my comfortable reading chair, go downstairs, and get to the front door, only to find that there's no one there and there's a package on the doorstep. I could have carried on reading and gone to pick up the package when I was done.

When I read, I try to leave my phone somewhere out of reach, as otherwise I tend to get sucked into doomscrolling instead of reading. It means that I can't easily check who is at the door when the doorbell rings. Since I knew it was possible to get the Kindle to show a fairly slow video feed of my Mac desktop, I thought it might be possible to do the same with the feed from my video doorbell .

I created an automation that took a snapshot of the video doorbell feed and saved it as a still image in Home Assistant. The process repeats every second, so that the snapshot image is updated every second.

I could get the video doorbell feed to display on the Kindle

A refresh rate of about a second was good enough

I set up the snapshot image to update once a second because I found that when I set up the Mac monitor for the Kindle , the image was able to refresh at a rate of about one frame per second. This meant that I should be able to get the Kindle to display the updated snapshot each second, effectively giving me a slow-refresh video feed.

Home Assistant serves the JPEG snapshot over HTTP, and a small script on the Kindle downloads the JPEG using wget . The image is drawn onto the Kindle screen, and then the whole process begins again; Home Assistant serves the next image, the Kindle downloads and displays it.

When I tested it out, it almost worked perfectly. The image appeared on the screen and refreshed every second, giving me a slow but workable stream of my doorbell. The problem was that only a fraction of the image was visible on the screen.

Getting the image to display at the right size was a real challenge

Chatbots were annoyingly useless

It felt like I'd done the hard part. Surely all I needed to do now was to resize the image to fit the Kindle's display. That should be easy, right?

I spent the next several hours tearing my hair out. I couldn't find any way to make this happen, and despite trying the three major chatbots, all three of them led me on a merry dance where they mostly just made things up or ignored my explicit instructions.

Eventually, after having to step away for a while before I lost my mind, I found a forum post about someone who had managed to install ImageMagick in the Home Assistant container. By doing the same, I was able to convert the image to the correct size to fit the Kindle's screen.

Finally, I was able to see the video doorbell images on my Kindle, refreshing at a rate of one image per second. This was more than enough to see who was at the door. I can start and stop the feed from within the KUAL menu on the Kindle , so whenever the doorbell rings, I can start the feed on my Kindle and see who is at the door.

---

Seeing my camera on my Kindle is genuinely useful

This was one of the most frustrating projects I've taken on recently, but in the end, I finally have a useful working way to check who is at the door directly from my Kindle. I find it pretty crazy what you can do with an obsolete and low-power eReader.