[PascalW]

I could replace ht with another HTTP client. I just picked it because it was the easiest way I knew to compile an HTTP client with statically linking openssl.

If anyone knows an easy way to compile curl with statically linked openssl, let me know!

It would also not be difficult to build a small custom client based on Hyper or Reqwest.

Though I'm not sure if it would actually make a large difference with only 20 screen refreshes per day.

[misterdata]

I wrote something like this using reqwest for a Waveshare 7.5inch display. Also includes a dithering step so all that is needed is a web server serving an image. No conditional requests though but should be easy to add. It is fully statically compiled (even uses musl and rustls), runs on a very bare-bones Linux environment on a Raspberry.

https://git.pixelspark.nl/pixelspark/sparkboard

[PascalW]

Nice work!

[tyingq]

If it's really just the screen refresh that's to be avoided, I think just comparing old download /new download with "diff -q" would be a reasonable solution. Of course, perhaps the Kindle doesn't have a diff binary. But maybe it has "sum" or "md5sum" or something else in that space.