Postcard frame

It was pretty clear after testing with the RPi that it was going to be a lot of work to get it into a state that worked robustly and was user friendly for non-technical people. So the next version I decided to move to an ESP-32, which used a lot less power, handled shutdowns much better, and could have much simpler code. I also decided to get my own website to serve the images, moving away from the email solution. I still like the email option, but I haven't worked out a good way to implement it yet.

This just used the esp32 dev board and didn't have a battery, but it was all I needed to work out the code on both the esp32 and the server. Originally I had the images just sitting in a public folder, which anyone could access if they worked out the (easily guessable) URL, but now they are served through a php script which requires a key specific to the "frame" making the request. The server has a database with the details and settings of the different frames (i have multiple running at once), which means some can have different resolutions, colour depths, update times and so on.

The frame itself was just a picture frame I bought from a supermarket, so looked passable from the front but of course a mess on the inside.

So the first version of this concept used a Raspberry Pi Zero and received the images by email. I liked how easy it was for anyone to send images by email, without needing to remember a link (although it needed a specific password in the subject line to be displayed). But the email was a googlemail account, which was a mess for me to set up without getting it blocked for accessing it automatically and so on. And I never fully trusted google not to change the service in a way that would break the system.

Also, the Pi was definitely overkill. It allowed a lot of nice onboard image processing options, but that really wasn't necessary, and the whole startup and graceful shutdown issues made the power supply a lot more complex. I used a nice 16bit greyscale e-paper display though, which looked really good and it had an 1872×1404 resolution, so it was actually quite hard to see that it wasn't a printed image. The contrast is better with the lower resolution displays I'm using now. Also, the high resolution display needed a bit more complicated driver, and was about double the price. I might go back to it in a future version.

My brother made a nice wooden frame for it, with a water jet cut and bent aluminium backing (still looking for the photos though). It looked quite nice but the inside was held together with blu-tac and tape, and was a mess of wires.