Practice Flight – 06/26/2016

I’m not in the habit of posting my flight videos, mostly because they’ve not been that interesting. But I’ve decided that should change. This weekend, I took my 250 class quad over to the local elementary school to get in some practice flying. Here are some of the interesting bits…

Tech Specs:

  • Quad Size: 250mm
  • Quad Weight: 976.7 g (she’s a fatty, I know)
  • FPV: Fatshark Predator V2
  • Recording Camera: GoPro Hero (original, a huge part of my weight)
  • FC: Flip MWC 1.5
  • ESCs: ReadyToFlyQuads F-30A
  • Motors: RTF Motor 2208 – 2300KV
  • Props: 5×4.5×3 Bullnose
  • Batteries: Turnigy 2200mAh 25-35C 3S
  • Radio: FlySky FS-T6

Back from CppCon 2015

Now that the dust has settled a bit and I’ve adjusted to being back on east coast time, I thought it’d be worth talking a little bit about CppCon 2015. CppCon, for those who haven’t heard about it, is a five day conference devoted to C++ (seven if you pay for an extra class). It’s a relatively new kid on the block, this year being only the second year. It’s certainly not the only C++ conference in town. But CppCon distinguishes itself from all the others in terms of scale. Attendance to C++Now, for example, is capped at around 150 people and features three tracks at any given time. C++ and Beyond describes itself as “small” and features only one track at a time over three days. This year, CppCon saw nearly 700 people in attendance. That’s a nearly 15% growth over last year’s 600 attendee count. The days start early and end late. And at any given point, there could be up to six separate tracks going on. Presenters include folks from Google, Microsoft, Boost, Adobe, etc. As you can imagine, there’s enough content at CppCon to satiate even the thirstiest of minds.

Just like last year, CppCon was held at the Meydenbauer Center in beautiful Bellevue, Washington, a Seattle “suburb” (I use that word loosely. See Wikipedia.) that just so happens to be in Microsoft’s backyard. The conference center itself has four levels. The bottom two floors have amphitheatre-sized conference rooms that are used for keynotes and larger talks. The top floor has a number of smaller classroom sized conference rooms and is where most of the action actually takes place.

Most of the rock stars showed up again this year – Bjarne Stroustrup, Herb Sutter, Andrei Alexandrescu, John Lakos, etc. (Scott Meyers was noticeably MIA this year). Bjarne’s keynote, “Writing Good C++14”, set the tone for everything that was to come. The theme seemed to be “move forward” – abandon your old compilers, modernize your legacy codebase, and leave the past in the past. This was reflected by the significant number of talks that revolved around C++17 proposals and technical previews that will be appearing in a compiler near you.



Me with Bjarne Stroustrup

Like any conference, the quality of presentations was a mixed bag. There were great speakers and some not so great. Some presentations were practical, some were meta, and some were sales pitches for third party libraries. All tech conferences are like this to some degree. For conferences with only one or two tracks, this can be a mild annoyance. But the fact that there was so much happening at the same time allowed attendees to be a bit more discerning.

What about schwag? Schwag is something we all pretend to not care about. After all, we’re only there for the knowledge right? Mmhmm. 🙂 There actually wasn’t much schwag to speak of. This year, attendees received a plastic bag containing some flyers, a deck of “Woman in Tech” playing cards, and a thumb drive containing an offline version of cppreference.com. There were no free shirts, despite being asked to provide shirt size at registration time. At one point, JetBrains started giving away yo-yos, CLion stickers, and copies of a mini-book entitled “C++ Today: The Beast is Back”, which happened to serve as the basis for Jon Kalb’s highly entertaining presentation of the same name.That was about it. Not even the meals were free, which seemed to surprise a lot of folks.

Apart from that, there weren’t many disappointments at CppCon. This conference has a lot to offer. The talks were great. All of the presenters were approachable and very personable. The atmosphere was positive. And, most importantly, it was FUN. Would I go back again?
Definitely. Should you go? Absolutely.

Timelapses with Android

My wife and I decided to add a deck to our home. It’s something we’d been discussing for years. Should it run the length of the house? Or should it be shorter? Narrower? Do we want to allow space for a future hot tub (which we’ll probably never get)? Built in pergola? Big stairs? Little stairs? It’s a conversation I think we could have kept having for many more years if we had indulged ourselves. But sometimes you just have to know when it’s time to make a decision and move on.

So we settled on a design, talked to contractors and code enforcement folks, and finally scheduled the build. I really, REALLY wanted to do a timelapse of the whole thing, but I wasn’t sure what to use. I considered using something like CHDK on my DSLR. The idea of leaving the camera out in the elements for days on end didn’t appeal to me. So I dismissed that idea fairly quickly. I had an old Samsung Galaxy S3 sitting in a drawer collecting dust and wondered if I might use that instead. It took decent photos. And if it died in the middle of the build, I wouldn’t be terribly heartbroken about it. So that’s the path I went down.

As a software developer, the instinct is to write software solutions for your own problems. I began listing out the things I would need in order to do the timelapse in Android – wake locks, a Service, an Activity for starting/stopping captures, a preview surface, camera code, storage code, etc. And then I began writing the app. No sooner had I started than I realized I only had 3 days before the builders began their work. So I backed away and began looking at what was already in the Play store.

That’s when I stumbled upon Lapse It Pro. It did everything I needed. And it allowed me to save full-frame, 8 megapixel image sequences as opposed to just a video – a bonus because I wanted to stitch the video together outside of the phone. I installed it on the S3 and had it working in no time. The UI is straightforward. And the entire capture process can be configured – frequency, video/image format, image size, etc. I fell in love with it right away. (I’m already thinking of new projects I can use it on.)

The next thing I needed to figure out was power. I would be placing the phone in or near trees, far away from any electrical outlets. As a test, I charged the phone completely and started a 1 frame per 30 second capture using just the phone’s battery. It lasted about 3 hours before it died. I next tried using a 4400mAh battery pack I picked up from Adafruit a year or so ago. That bumped my capture time up to about 6 hours. Good, but not good enough. It was also a 1A pack, so it couldn’t charge my phone as fast as the phone was discharging. I really needed about 10 hours of life with a 2A supply. That’s when I found a 18000mAh pack on Amazon for $33. It had a port that could deliver 2A. And so it was perfect for my needs.

The video above is the fruit of my labor. The 3D modeling was done using 3DSMax. The morphing towards the end was done with FantaMorph(another fantastic piece of software). And the whole video was stitched together using Adobe Premiere. I ended up needing to apply the Warp Stabilizer effect to the timelapses because it was windy out and the ladder supporting the phone shook quite a bit.