I haven’t actually started coding yet with the ESP chip. In my case the aim is to pick up a preformatted image from an URL, avoiding all of the finicky formatting you describe. I like the idea of the screen controller as a single function machine just for display, with the backend being a simple GitHub repo connected to Cloud Run via CI/CD.
Yes, it can get pricey. I'm using a Raspberry Pi Zero W with a Waveshare 7.5 e-ink panel, which came with its own raspberry Pi driver. I also added a PiSugar2 battery. Waveshare seemed to be the most affordable option out there.
I find the costs to be reasonable, but I just bought a Waveshare e-ink ESP32 controller to try boosting battery life, since I don't need a fully fledged OS. All I'm doing on the frame is pulling an image from an URL or displaying a local image if the connection fails.
Very cool ! I built a series of scripts to exchange e-ink images through Gmail last year which I baptized DispatchPi (https://github.com/malcolmosh/dispatchPi/blob/main/README.md) and a program like this would definitely have accelerated development. It was a bit fussy to always have to use a terminal to SSH into the Pi, then update the scripts through FileZilla (ftp client) + Vscode.
I've just completed a dashboard project which I'm about to release and I was also thinking of switching my frame drivers to ESP32 to run them on batteries, since they consume far less energy than even a Pi Zero. So +1 for ESP32 compatibility if time allows!