for a similar project you can look at my
https://github.com/yparitcher/kindle-zmanim
it uses fbink to display a dynamic screensaver.
It is currently written in C, but if you look at the earlier commits most of it used to be in shell if that is easier for you
for my details see my other posts on this topic
https://www.mobileread.com/forums/sh...8&postcount=27