qr-backup

qr-backup is a program to back up digital documents to physical paper. Restore is done with a webcam, video camera, or scanner. Someday smart phone cameras will work.

I’ve been making some progress on qr-backup v1.1. So far I’ve added:

  • --restore, which does a one-step restore for you, instead of needing a bash one-line restore process
  • --encrypt provides password-based encryption
  • An automatic restore check that checks the generated PDF. This is mostly useful for me while maintaining qr-backup, but it also provides peace-of-mind to users.
  • --instructions to give more fine-tuned control over printing instructions. There’s a “plain english” explanation of how qr-backup works that you can attach to the backup.
  • --note for adding an arbitrary message to every sheet
  • Base-64 encoding is now per-QR code, each QR is self-contained.
  • Codes are labeled N01/50 instead of 01/50, to support more code types in the future.
  • Code cleanup of QR generation process.
  • Several bugfixes.

v1.1 will be released when I make qr-backup feature complete:

  • Erasure coding, so you only need 70% of the QRs to do a restore.
  • Improve webcam restore slightly.

v1.2 will focus on adding a GUI and support for Windows, Mac, and Android. Switching off zbar is a requirement to allow multi-platform support, and will likely improve storage density.

Getting the Adafruit Pro Trinket 3.3V to work in Arch Linux

I’m on Linux, and here’s what I did to get the Adafruit Pro Trinket (3.3V version) to work. I think most of this should work for other Adafruit boards as well. I’m on Arch Linux, but other distros will be similar, just find the right paths for everything. Your version of udev may vary on older distros especially.

  1. Install the Arduino IDE. If you want to install the adafruit version, be my guest. It should work out of the box, minus the udev rule below. I have multiple microprocessors I want to support, so this wasn’t an option for me.
  2. Copy the hardware profiles to your Arduino install. pacman -Ql arduino shows me that I should be installing to /usr/share/aduino.  You can find the files you need at their source (copy the entire folder) or the same thing is packaged inside of the IDE installs.
    cp adafruit-git /usr/share/arduino/adafruit
  3. Re-configure “ATtiny85” to work with avrdude. On arch, pacman -Ql arduino | grep "avrdude.conf says I should edit /usr/share/arduino/hardware/tools/avr/etc/avrdude.conf. Paste this revised “t85” section into avrdude.conf (credit to the author)
  4. Install a udev rule so you can program the Trinket Pro as yourself (and not as root).
    # /etc/udev/rules.d/adafruit-usbtiny.rules
    SUBSYSTEM=="usb", ATTR{product}=="USBtiny", ATTR{idProduct}=="0c9f", ATTRS{idVendor}=="1781", MODE="0660", GROUP="arduino"
  5. Add yourself as an arduino group user so you can program the device with usermod -G arduino -a <username>. Reload the udev rules and log in again to refresh the groups you’re in. Close and re-open the Arduino IDE if you have it open to refresh the hardware rules.
  6. You should be good to go! If you’re having trouble, start by making sure you can see the correct hardware, and that avrdude can recognize and program your device with simple test programs from the command link. The source links have some good specific suggestions.

Sources:
http://www.bacspc.com/2015/07/28/arch-linux-and-trinket/
http://andijcr.github.io/blog/2014/07/31/notes-on-trinket-on-ubuntu-14.04/