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!

Speaking at BayCon 2019 this morning!

I’m pleased to say that I am one of the speakers lined up to give a talk at BayCon 2019 here in Silicon Valley this morning. I’ll be giving the talk “APRS Turns 35. What’s Next“, which looks at the current state of APRS, especially mobile and pedestrian mobile APRS. I’ll post a link to the audio or video of the talk when it’s available. If you want to use the materials as a basis for your own talk, you can get it at GitHub and make a fork.

#Jamuary, Day 15

This track was a lot harder for me because I was queuing up each transition manually. I’m starting to begin to get a feel for what “playing live” on the OP-Z is like once you get tracks set. It’s fun, but challenging at this tempo with my fat fingers!
Now that I’ve reached the halfway point in the month with this, I’m seeing some trends in my work. It’s easy to start to get stuck in a rut, especially because I’m timid about trying new things — like today’s sketch. I had in my mind clearly what I wanted to do, and I think with this sketch I got close. It’s all pretty basic looping stuff, but I’m triggering the muting and unmuting of each track by hand, and in fact this is two patterns (one without the running high hats, one with) with different tracks in each pattern muted. It’s going to take some practice before I can do that kind of manipulation quickly and in-tempo — I have a lot more regard now for the other OP-Z players I’m seeing on Instagram and YouTube!