Kindles are fun devices to hack and play with. I can grab an old kindle for €15-20 on eBay.

I did the same last year and had lots of fun in the process.

https://samkhawase.com/blog/hacking-kindle/

I love using Kindle's as single purpose tablet/interfaces/displays. I'm the weirdo who actually prefers the LCD displays vs eInk and it's incredibly easy to set Kindle Fire's into dev mode which lets you display a webpage, never turn off while connected to power and never show ads.

You can regularly find the Kindle Fire HD10s for ~$40

For some reason, this project reminds me of this one:

https://engineersneedart.com/systemsix/systemsix.html