It’s looking more like a fence
One of the things we’ve been meaning to get done is to move our backyard fence to the outer limits of our property lines. For some reason when the fence was first built, the fence was put 8-20 feet inside of our property, leaving the rest our of property essentially abandoned. Miss Ruth had adopted our property on her side of our fence and we never had the heart to “take it back” while she lived here, so when we got new neighbors it seemed time to make the change.
Only I’d never built a fence before.
Enter YouTube. You can learn anything on YouTube.
I have had a 3DR Solo drone since last summer and have been looking for interesting ways to expand its capabilities. One thing that I thought should be possible is to stream live video from the drone while it’s in flight. The Solo controller has an HDMI port to push video to a monitor but I wanted to see if I could get to the video stream directly, through software. I’m proud to say that I figured out how to do it.
First you need a separate computer, preferably a laptop or something portable. The computer will need to connect to the WiFi network that the Solo controller creates. Once you’ve got your computer joined, make sure it’s connected by pinging the controller (IP address 10.1.1.1).
Next, create an SDP file on your laptop as discussed on the 3DR Solo wiki.
c=IN IP4 10.1.1.1
m=video 5600 RTP/AVP 96
… save this as sololink.sdp.
The controller will only stream video if it’s got a TCP connection from the host requesting a stream. In a terminal window, connect to the controller as follows:
telnet 10.1.1.1 5502
nc 10.1.1.1 5502
Now the controller should be able to stream video using a tool such as VLC or ffmpeg. For VLC, open the osololink.sdp file you created above. You should see the drone video appear on your laptop. VLC is nice for checking the video but I haven’t worked out how to send it to YouTube yet. I believe it does not properly handle the RTMP media format that YouTube needs, though I’m not sure of this.
It’s nice when your server fits in your mailbox.
I’ve always liked to have a home server hanging around for things like email, file sharing, and the like. Over the years this has taken the form of a beefy desktop computer, a PowerPC-based MacMini, an embedded Linux-based router, and recently a beat-up old laptop. All had their challenges, power consumption and fan noise being the two main ones, though the PowerPC machine and the router also couldn’t run all the software I needed. I was limping along on my busted laptop for as long as I could but decided it was nearing the end of its useful life. It was time to go shopping for something that would last me a while.
The embedded idea still appealed to me for the two main reasons I mentioned above: power consumption and noise. I wanted something that sips electricity and was quiet yet still provided enough computing power to do what I needed. After reading up on some online reviews, I went with the Intel NUC.
Intel’s NUC (“Next Unit of Computing”) systems are embedded x86_64 machines which are about half the size of a brick. They have plenty of ports: HDMI, USB 3.0, and even a Thunderbolt port. They come with your choice of Intel processors, whether it is an i3, i5, or i7 series. Memory can be boosted to 32 GB and it accepts newer SSD drives. Some models can fit 2.5″ laptop drives as well. The hardest part about making the jump to an Intel NUC was simply deciphering which Intel model had which options. Sometimes having too many choices isn’t a good thing, I suppose.
I’d spent many evenings last week going door to door along State Street, methodically collecting signatures on a city petition to reduce the State Street speed limit to 25 MPH from its current 35 MPH. The first two days garnered the lion’s share of signatures; before I knew it I was up to ten. The last four, however, have been a challenge. Some neighbors tell me they agree 100% with reducing the speed and yet they’re very reluctant to put their name on the list. Some of these neighbors are older and some are renters who are perhaps worried any more neighborhood improvements might price them right out of the home they are renting. It’s hard to know what their real reasons are but it’s frustrating that they want it done and yet don’t want to do anything to make it happen.
Sunday afternoon I was particularly bummed when some friends I thought I could count on to sign decided against it, citing the mess that the water main replacement/traffic calming on Glascock has been. Even though I stressed it was only a new set of speed limit signs I could not convince them. I felt like chucking my clipboard into the street and giving up on the whole damn process. It would be just like five years ago, when I spent hours walking up and down State only to collect just enough signatures to barely miss the threshold.
No sooner had I written my previous post that I got a boost of civic energy, this one from attending Monday night’s East CAC meeting. It had been a long while since I had been to a meeting, with my involvement in the Ligon PTA taking up much of my free time as well as other things like Friends of Dorothea Dix Park.
Monday’s meeting featured information on the purchase of Gateway Plaza, right outside of my neighborhood, so it provided a compelling reason to be there. There wasn’t much information provided but seeing many of my friends and neighbors there after such a long time was really fun. The same boost of energy I always got when conducting East CAC meetings was still there. My neighborhood inspires me! It’s good to know I can always come back.
A RTLSDR receiver and dump1090 can track planes hundreds of miles away.
As an amateur radio operator and full-time geek, I’ve always been interested in the convergence of technologies, especially when the convergence scratches a few of my itches. One one of my latest hobbies is tracking commercial airliners through their ADS-B broadcasts. It’s a hobby that doesn’t take much time outside of setting it up. In about two hours, I configured a receiver, built an antenna, and set up software that shares what I find with the world, and all for under $30. Here’s how I did it.
The ADS-B protocol is a digital “status update” signal broadcast by airplanes which updates other aircraft around it with important location information and the like. The FAA would eventually like to see ADS-B take the place of ground-based radar but not all airplanes use it yet. Transceivers are still pricey and owners of general aviation aircraft like Cessnas largely haven’t yet adopted the system. There’s an amazing amount of data being sent and anyone with the proper receiver can intercept it (oops, that’s what we called radio reception when I was a Navy cryptologic technician), and that receiver can be dirt-cheap like the RTLSDRs.
Three years ago the radio-geek world was set ablaze when it was discovered that a mass-market DVB-T USB device had the ability to become a software-defined radio, basically a wide-range receiver that can easily decode almost any signal. Hobbyists soon were using these $15 RTLSDR dongles for just about everything, including tracking airplanes. I had a few lying around that weren’t really being used for anything so I hooked one up to my Raspberry Pi
This story has captivated me since I read it a few days ago. It has inspired me to maybe actually do something with those little side projects I’m always dreaming up.
I was first introduced to Hoverboards while watching Casey Neistat’s daily vlogs on YouTube. I thought, “Wow. That’s pretty cool!” and started searching online to purchase one myself. When I looked at the cost of an IOHawk at $1,800 or the Phunkeeduck at $1,500, I thought there had to be a cheaper way. That’s when I found out how cheap they would be if you bought them online in bulk straight from the manufacturer.
That was an intriguing idea, so I decided it wouldn’t hurt to order straight from China. I thought I would keep one and sell one, and if I could sell one, then maybe I could sell more. So I began the process.
Source: How I built a hoverboard company and then blew it up | TechCrunch
Oakwood CERT members learn basic firefighting
I’ve blogged here before about how much fun I’ve had participating in the CERT program,
the Community Emergency Response Team training. I think it is important to get people trained to help themselves when the need arises. In cases of trauma, every minute counts. Medical experts talk about the Golden Hour,
when the odds of saving a victim of traumatic injury are greatest. One doesn’t have to be a doctor, but anything that can patch a person up until medical professionals can get there will go a long way towards saving them.
As you know, the first CERT program folded. I had heard rumblings of a new program being bootstrapped in the Oakwood neighborhood. A year passed and I wondered if the effort would succeed. Then in August I got an invite to the training class for the Oakwood CERT team – it was actually happening! About twenty of my neighbors took the training with me and we had great support from Samantha Royster from the North Carolina Department of Public Safety (NCDPS). Everyone left that weekend with some hands-on emergency training as well as a full CERT kit paid for through a generous federal grant.
What’s more, my classmates immediately elected me … president. While I wasn’t in the room, of course. Heh.
Fast forward to mid-December. My company’s foundation looks for non-profits that attract the passion of its employees and those employees are invited to submit grant requests. On the last day of the grant program, I put in a request to fund the Oakwood CERT team and was pleased to learn it was fully granted! It’s a modest grant but it’s one I hope to build on.
Travis’s green screen setup. Lights are helpful but not necessary.
Since the office was officially working a half-day Wednesday due to it being the day before Thanksgiving, I decided not to make the monotonous one-mile commute into the office and instead worked from home. Being geographically dispersed, my team meets daily via videoconference and I decided I was done with putting the walls of our spare bedroom on display for my coworkers to see.
The day before a holiday called for something a little more whimsical, so I hatched a plan. I found some free software for the Mac called CamTwist that can do chroma key. Chroma key is the “green screen” technique that TV studios use to insert backgrounds behind their reporters and presenters. A few years ago our son, Travis, got a green cloth that makes a decent green screen. I borrowed his green cloth, set it up behind my office desk, fired up CamTwist, and displayed a holiday-appropriate scene behind me of wild turkeys in the woods. My coworkers loved it!
It would make a cool art project to cast the hands of people who work in various vocations and display them together.