K.C.'s Garage

This post is a quick list of the steps it took to install mitmproxy on a vanilla Raspbian Jessie install on a Raspberry Pi.  The compile steps take quite a while, which made the trial-and-error method of figuring out which libraries were missing to be a painful process.  Hopefully this post will make it easier for anyone else trying to do the same thing. Naturally, do $ sudo apt-get update && sudo apt-get upgrade  first to bring everything up to date. Missing libraries: python-dev libxslt1-dev libxml2-dev libffi-dev libssl-dev Fairly simple, just do: $ sudo apt-get install python-dev libxslt1-dev libxml2-dev libffi-dev libssl-dev  Out-of-date library: mitmproxy requires pyasn library >= 0.1.8.   (As of this writing, the latest in the repo is 0.1.7) Check your installed version: $ dpkg -l | grep pyasn                                   ...

We've had this cool inexpensive Jada Toys "2006 Camaro" R/C car for several years now. The batteries are worn out, the controller doesn't work well anymore and it had been relegated to just being a regular "toy car" for my four year old. I was cleaning my electronics bench yesterday and realized I probably had enough spare parts from my other R/C ventures to gut and rebuild the Camaro with more modern parts.  Sure, the parts probably cost more than the car did, but I already had them so why not? The first order of business was assessing whether the existing mechanisms in the car are serviceable at all.  After removing the 13  required screws to get the body off the chassis, we get a good view of the inside: The brushed motor / gear-differential assembly (right) are probably either usable as-is or not usable at all, so I decide to keep them intact and try just driving them with a brushed motor speed controller. The receiver / control c...

A while back I purchased some generic STM32F103C8T6 development boards on eBay for about $4 each.  I initially had some limited success programming them using the GCC ARM Embedded (eabi) toolchain and a generic STM32 loader program.  Since then I've discovered a project to get them working with the Arduino 1.5+ toolchain. There's a lot of different information about the various STM32 boards out there.  I'm documenting my notes here mostly for my own sanity since I don't play with these boards often.  Maybe you'll find it useful too. Arduino hardware library for these boards: https://github.com/rogerclarkmelbourne/Arduino_STM32 "Support" forum:  http://www.stm32duino.com/ The USB port The generic boards do not have a meaningful USB bootloader.  The USB port is only useful for power.  (TODO: Flash the "Maple Mini" bootloader onto them for future ease of use?) Arduino Board Selection & options Tools -> Board -> Generic S...

While working on my instrument training, it occurred to me that I had everything I needed in my parts bin to build a device to help alert me to deviations in altitude. So, I built MonkeyAltimeter. It started off on a breadboard while I worked on the code: Then, I took it for a flight test (primarily to see how accurate it was in the cabin and see if my VSI routine worked): Finally, I designed and printed a simple case for it: The details,  parts list, operation manual, &etc are here: http://www.thingiverse.com/thing:942832 The source code is here: https://github.com/phreakmonkey/MonkeyAltimeter Enjoy!

I  have finally submitted my comments to the FAA's NPRM for model aircraft. After reading the proposed regulations, reading the responses from various advocacy groups, and considering both sides I have submitted the following. If you would like to comment to the FAA as well, the link is here: http://www.regulations.gov/#!docketDetail;D=FAA-2015-0150 The deadline for comments is April 24th, 2015. ---------- I am a computer engineer, r/c model enthusiast, private pilot, and aircraft owner. I am writing in response to the FAA's proposal to regulate small unmanned aircraft systems, including model aircraft. I support the exemption of recreational model aircraft from the regulation of unmanned aircraft systems. I understand the critical need to maintain separation of the increasing proliferation of radio control and hobbyist unmanned aircraft ("model aircraft") from other aircraft in the national airspace system. I do not agree that trying to interpret model aircr...

The FAA's NPRM for operation of unmanned aerial systems has been published as of today. Most of the commentary online is about the commercial use of UASs, which is, by far, the most interesting aspect. However, many are dismissing the entire NPRM as "having nothing about recreational flying." This isn't exactly the case.  This post will address my reaction for recreational / hobbyist use. The NPRM has an important distinction for recreational use- it adds Subpart E to " PART 101—MOORED BALLOONS, KITES, AMATEUR ROCKETS AND UNMANNED FREE BALLOONS ", establishing the definition and rules for recreational flying.   By and large, it just codifies into law the existing requirements of the previous advisory circular. It is largely very reasonable. That said, so far I have two comments on this I will be submitting to the FAA.  This is my initial reaction, so my specific comments and wording may change as I have more time to read and consider this docu...

I was doing some fast, straight line FPV flying with one of my quadcopters and a few things struck me about how multicopters fly in a straight (horizontal) line; The more you pitch forward (to go faster) the less aerodynamic you are The angle of the pitch actually serves to reduce lift, effectively fighting the motors Finding the maximum forward speed is a risky, manual process. So what if you wanted to build a multicopter optimized for forward flight?  I've seen some 250mm FPV racers that actually had the front two motors angled forward to increase the forward speed at a lower pitch angle.  I found myself asking - what if you could dynamically actuate the front motors forward instead of pitching the whole aircraft?  (Similar to the motors on an Osprey, but sans wings.) Vectored thrust on multirotors is uncommon, but not new.  Still, this idea has a singular purpose which makes working out the details and controls a bit easier. So, I decided to build one....

Class: Nebula (F330) Date Built: 2014.04.22 Date Lost: 2015.01.02 Today we declare Phoenix - my primary FPV quadcopter - LOST .  Its final flight was Friday, 2 Jan 2015 in the large private dirt field that I like to fly at.  I was performing some aggressive acrobatics when something on the quad failed, sending it into the infamous quadcopter death spiral. Despite knowing where it failed and roughly where it went down - the quad was not located at the crash site.  I had a colleague join me in the search, and we gave up after an hour.  Two subsequent returns to the area and I have concluded that we can't find it because it is in fact no longer at the crash site.  My current working theory is that someone from the neighboring park saw it go down and took it in the few minutes between the crash and my going to retrieve it. :( This was the aircraft that I learned FPV flying on. It will be missed. Phoenix final specifications: Frame: F330 Quadcopte...