CUPS-PDF Printing to an iPad via DropBox using a Raspberry Pi

Inspired by printing to a reMarkable tablet. You need to have Dropbox installed on your iPad, and/or a PDF viewer that supports Dropbox syncing.

1. Follow the instructions here to install CUPS PDF printing on your Pi and set it up as a print server.
2. Patch the PPD to avoid the problem of printing blank pages (steps here). You’ll need to scp /usr/share/ppd/cups-pdf/CUPS-PDF.ppd to someplace where you can do an upload from your browser.
3. Install Andrea Fabrizi’s Dropbox Uploader script from here.
4. Make a directory in your Dropbox to hold your PDFs. I chose _ so it would show up first in my list of files, to make scrolling easy.
5. Crontab uploads of your PDFs. Do crontab -e, and add an entry such as

0-59/1 * * * * /home/kf6gpe/Projects/Printing/Dropbox-Uploader/dropbox_uploader\
.sh -f /home/kf6gpe/.dropbox_uploader -s upload /home/kf6gpe/PDF _

You’ll need to change the path to your dropbox uploader, the configuration file, the path to your PDF directory locally on the Pi, and your remote directory. Keep the -s flag, which tells the uploader to only upload changed files!