This section contains notes I've written on quadrotors, mainly about the Pixhawk hardware and the PX4 autopilot firmware.

• About the PWM output of Pixhawk, 2015/12/16
• Upload the Bootloader of Pixhawk, 2015/12/08
• Calibration Procedure of the PX4 Firmware Part I, 2015/11/13
• What is going on behind the calibration procedure of QGroundControl, 2015/11/13

• Some Matlab Plot Tricks
• Maniuplate EPS figures generated by Matlab, 2013/10/09
• Manipulate pdf files with ghostscript
• Crop pdf files with ghostscript
• Matlab codegen problem on Mac OS X 10.7

• Separate folders for figures and bib files in LaTeX

• Using ROS with Docker in macOS, 2017/06/07
• Converting and Joining pdf Files in MacOS, 2017/05/16
• Excessively large syslog files, 2017/05/01
• Install Gentoo from a USB Disk, 2016/01/04
• Editing lines before and after search patterns in Vim
• Collections of some bash commands
• Find out 777 folders and change permissions
• Some Linux Command Line Tricks
• On files starting with dot and dash
• Rename files in Mac OS, 2013/10/16
• Create a bin folder at your own home folder in Linux
• Commands to show system information on Linux

• Install Hadoop on Virtualbox virtual machines, 2017/10/08
• Plot the Geographical Locations of IP Addresses, 2017/06/13
• Automatically Renew Let's Encrypt SSL certificates using Cron Jobs, 2017/05/02
• Use Let's Encrypt SSL certificates on a Godaddy hosted site, 2017/02/16

• [Book Review] The Dialogues of Plato - Symposium, The Apology, Phaedo by Plato, 2018/09/13
• [Book Review] On Writing Well by William Zinsser, 2018/09/13
• [Book Review] The Unbearable Lightness of Being by Milan Kundera, 2018/09/13
• [Book Review] 84, Charing Cross Road by Helene Hanff , 2018/04/30
• [Book Review] Skyfaring: A Journey with a Pilot by Mark Vanhoenacker , 2017/10/08
• [Book Review] The Coffee Roaster's Companion by Scott Rao , 2017/05/06
• [Book Review] The Blue Bottle Craft of Coffee, Growing, Roasting, and Drinking, with Recipes, 2017/04/18
• On English writing, 2014/09/03
• Notes on Divination with the I Ching

• Refractometer and Coffee Extraction, 2017/05/16
• Some examples of Imagemagick convert, 2014/07/20
• Display synonyms in command line, 2014/07/10
• Generating flashcards with Linux and Latex

• Covariance Matrix and the Matrix of Inertia, 2017/07/31
• Sketch with least-squares, 2014/06/20
• What does the word "Programming" mean in "Dynamic Programming"

• Notes