penk | Entries tagged with hack

It’s no secret I’m a huge fan of Warner Brothers cartoons. My sister and I were basically raised on this stuff, and so much of our cultural reference points (and humor) comes from watching Bugs Bunny when we were growing up.

So, as Halloween approached, I thought it might be cool to recreate an iconic image from the 1952 cartoon “Water Water Every Hare”, where Bugs is taken to a big scary castle on the edge of a waterfall. The castle is inhabited by, naturally, an Evil Scientist, who advertises the fact with a blinking sign on the towers of his castle.

Okay, I’m not really a scientist, I’m an engineer, but I figure I could apply a little artistic license and make a sign like that for my house for Halloween.

I wanted it big enough so I could put it in an upstairs window and have it visible from the pathway. We get a LOT of kids through our community over Halloween, and tons of parents as well (since mostly the parents would get the reference), so it needed to be visible. In order to constrain the glare, I decided to put it in basically a shadowbox configuration. An enclosed box, LED lighting inside, with a cutout pattern on front that would show the text.

First step was to use the laser cutter at the Makerspace to cut out the lettering. As anyone who does stencils will recognize, the second line (“BOO”) would have floating elements in it, and would have to be glued down after the box was made.

I found some old acrylic sheeting that still had one strip of white backing on that, and that made a dandy diffuser, as well as a place to mount the center parts of the lettering.

Next, based on the size of the lettering, I whipped up a box out of some scrap wood, and painted it black. I also painted the letter stencils so the shadowmask wouldn’t show up at night, but the lettering shining through would.

The colored lighting was done with some LED strips and an arduino. The sketch was painfully simple. Just first row on, wait a second, off, wait a half second, second row on, wait a half second, off, then wait a half second and then repeat. The most challenging part was soldering up the strips (I needed 3 rows), and mounting the arduino.

The only thing I had to go ‘buy’ was the backing board. A quick trip to Michaels got me a sheet of the plastic corrugated ‘cardboard’ for $4. This stuff is awesome, and I think I’m going to use it more in future projects. I mounted the LED strips and the arduino to it initially using hot glue, but while that’s the default ‘go to’ for DIY projects, I ended up ziptying the strips to the backing board, and doing the same for the arduino. Since the board is flexible, hot glue just didn’t make sense.

"" (Watch on YouTube)

Once everything was screwed together, it was just a matter of putting it in the window and plugging it in. Yay! It worked!

I slightly misjudged the width of the window, so it doesn’t quite have the margins I had hoped, but when it got dark, it looked great. Very happy with the end result!

About a year and a half ago, I bought a Synology 216+ NAS . The primary purpose was to do photography archiving locally (before syncing them up to Amazon S3 Glacier for long term storage). The box has been a rock solid tool, and I’ve been slowly finding other uses for it. It’s basically a fully functional Linux box with an outstanding GUI front end on it.

One of the tools included with the NAS is called ‘Surveillance Station’, and even though it has a fairly sinister name, it’s a good tool that allows control and viewing of IP connected cameras, including recording video for later review, motion detection, and other tidbits. The system by default allows 2 cameras free, but you can add ‘packs’ that allow more cameras (these packs are not inexpensive – to go up to 4 cameras cost $200, but given this is a pretty decent commercial video system, and the rest of the software came free with the NAS, I opted to go ahead and buy into it to get my 4 cameras online).

It just so happens, in September, 2017, we had a contractor come on site and install solar panels on several houses within our community. What I really wanted to do is use the Synology and it’s attached cameras to not only record the installation, but do a timelapse of the panel installs. Sounds cool, right?

Here’s how I did it.

The Cameras

The first thing needed obviously were cameras. They needed to be wireless, and relatively easy to configure. A year or two ago, I picked up a D-Link DCS-920L IP camera. While the camera is okay (small, compact, pretty bulletproof), I was less than thrilled with the D-Link website and other tools. They were clunky and poorly written. A little googling around told me “hey, these cameras are running an embedded OS that you can configure apart from the D-Link tools”. Sure enough, they were right. The cameras have an ethernet port on them, so plugging that into my router and powering up let me see a new Mac address on my network. http://192.168.11.xxx/ and I got an HTTP authentication page. Logging in with the ‘admin’ user, and the default password of… nothing (!), I had a wonderful screen showing me all the configuration options for the camera. I’m in!

First thing, natch, I changed the admin password (and stored it in 1Password), then I set them up to connect to my wireless network. A quick rebooot later, and I had a wireless device I could plug into any power outlet, and I’d have a remote camera. Win!

Next, these cameras needed to be added to the Synology Surveillance Station. There’s a nice simple wizard in Surveillance Station that makes the adding of IP camera pretty straighforward. There’s a pulldown that lets you select what camera type you’re using, and then other fields appear as needed. I added all of my cameras, and they came up in the grid display no problem. This is a very well designed interface that made selecting, configuring, testing, and adding the camera(s) pretty much a zero-hassle process.

If you’re planning on doing time lapses over any particular length of time, it’s a good idea to go into ‘Edit Camera’ and set the retention timeperiod to some long amount of time (I have mine set to 30 days). This’ll give you enough room to record the video necessary for the timelapse, but you won’t fill your drive with video recordings. They’ll expire out automatically.

At this point you just need to let the cameras record whatever you’ll be animating later. The Synology will make 30 minute long video files, storing them in /volume1/surveillance/(cameraname).

For the next steps, you’ll need to make sure you have ssh access to your NAS. This is configured via Control Panel -> Terminal / SNMP -> Enable ssh. DO NOT use telnet. Once that’s enabled, you should be able to ssh into the NAS from any other device on the local network, using the port number you specify (I’m using 1022).

ssh -p 1022 shevett@192.168.11.100

(If you’re using Windows, I recommend ‘putty’ – a freely downloadable ssh client application.)

Using ‘ssh’ requires some basic comfort with command line tools under linux. I’ll try and give a basic rundown of the process here, but there are many tutorials out on the net that can help with basic shell operations.

Putting It All Together

Lets assume you’ve had camera DCS-930LB running for a week now, and you’d like to make a timelapse of the videos produced there.

ssh into the NAS as above

Locate the directory of the recordings. For a camera named ‘DCS-930LB’, the directory will be /volume1/surveillance/DCS-930LB

Within this directory, you’ll see subdirectories with the AM and PM recordings, formatted with a datestamp. For the morning recordings for August 28th, 2017 ,the full directory path will be /volume1/surveillance/DCS-930LB/20170828AM/. The files within that directory will be datestamped with the date, the camera name, and what time they were opened for saving:

Next we’ll need to create a file that has all the filenames for this camera that we want to time. A simple command to do this would be:
```
find /volume1/surveillance/DCS-930LB/ -type f -name '*201708*' > /tmp/files.txt
```
This gives us a file in the tmp directory called ‘files.txt’ which is a list of all the mp4 files from the camera that we want to timelapse together.

It’s a good idea to look at this file and make sure you have the list you want. Type
```
pico /tmp/files.txt
```
to open the file in an editor and check out out. This is a great way to review the range of times and dates that will be used to generate the timelapse. Feel free to modify the filename list to list the range of dates and times you want to use for the source of your video.

Create a working directory. This will hold your ‘interim’ video files, as well as the scripts and files we’ll be using
```
cd 
mkdir timelapse
cd timelapse
```

Create a script file, say, ‘process.sh’ using pico, and put the following lines into it. This script will do the timelapse proceessing itself, taking the input files from the list creatived above, and shortening them down to individual ‘timelapsed’ mp4 files. The ‘setpts’ value defines how many frames will be dropped when the video is compressed. A factor of .25 will take every 4th frame. A factor of .001 will take every thousandth frame, compressing 8 hours of video down to about 8 seconds.
```
#!/bin/bash

counter=0;
for i in `cat /tmp/files.txt`
do
    ffmpeg -i $i -r 16 -filter:v "setpts=0.001*PTS" $counter.mp4
    counter=$((counter + 1))
done
```

Okay, now it’s time to compress the video down into timelapsed short clips. Run the above script via the command ‘. ./process.sh’. This will take a while. Each half hour video file is xxx meg, and we need to process that down. Expect about a minute per file, if you have a days worth of files, that’s 24 minutes of processing.

When done, you’ll have a directory full of numbered files:
```
$ ls
1.mp4
2.mp4
3.mp4
```

These files are the shortened half hour videos. The next thing we need to do is ‘stitch’ these together into a single video. ffmpeg can do this, but it needs a file describing what to load in. To create that file, run the following command:

ls *.mp4|sort -n| sed -e "s/^\(.*\)$/file '\1'/" > final.txt

Now it’s time to assemble the final mp4 file. The ‘final.txt’ file contains a list of all the components, all we have to do is connect them up into one big mp4.
```
ffmpeg -f concat -safe 0 -i final.txt -c copy output.mp4
```

The resulting ‘output.mp4’ is your finalized video. If you’re working in a directory you can see from the Synology desktop, you can now play the video right from the web interface. Just right click on it, and select ‘play’.

Here’s two of the three timelapses I did, using a remote camera in my neighbors house. Considering the low quality of the camera, it came out okay…

This entire tutorial is the result of a lot of experimentation and tinkering. There are holes, though. For instance, I’d like to be able to set text labels on the videos showing the datestamp, but the ffmpeg that’s compiled on the NAS doesn’t have the text extension built into it.

Let me know if you have any suggestions / improvements / success stories!

Even though I’m not working on CONGO as much anymore, I’m still helping out with registration at a couple events, and I’m always looking for better tools and gear to use. I originally designed registration to use cheap, network bootable PC’s, but that was so 15 years ago. The new hotness are small, inexpensive tablets. So could you put together a registration environment using some cheap tablets? Sure.

I’m helping an event that’s using EventBrite for registration services. I’d helped out at a different event about a year ago, and was impressed with the tools Eventbrite offered. The best part was the Eventbrite Organizer, a mobile app for IOS and Android that basically gave you a live dashboard, but also allowed super-fast checkins using a QR code scan. Think of scanning a boarding pass when boarding an airplane. The process is very similar.

The only drawback was, I needed a series of tablets that were roughly the same (bringing batches of workstations that are all different is a sure way to headaches). I didn’t think buying a stack of iPads was going to make sense, and el cheapo tablets from ebay and amazon are sketchy.

3 Kindle Fires being configured as registration terminals

I saw a deal come across Woot for Amazon Fire HD 7″ Tablets for… $33. Each. After digging around on the net, it looked like it was possible to load non-amazon software on these, it just took a little bit of jiggling. I’ve rooted Android tablets before, but it’s not a pleasant experience. I was seeing documentation that allowed for the Play store to be activated without a lot of yak shaving, so I decided to go all in.

I ordered 3 of the tablets, and they arrived a few days later.

First impressions – these are really nice. The design and polish is excellent, they fit well in the hand, and have exceptional screens. They have excellent battery life, and front and rear facing cameras. For $33, there’s not much to go wrong with here.

Here’s the steps I went through to get them up to ‘useable’ status.

First, charge them up, natch. They have great batteries, and the entire upgrade process and installation can happen on battery, but really, just get ’em charged.
Next, power up and log into your Amazon account. All the Fires have to be tied to an amazon login. Using the same one on each is fine (Amazon supports many Kindles per account).
Continuously go into the System settings (swipe down from the top) and select Device Information -> System Update. There’s a good 6 full OS updates that have to happen to bring your device up to FireOS 5.3.x or later. This can take upwards of an hour and a lot of reboots, but at the end, you’ll have a fully upgraded device.
Next, we’re going need to install APK’s that are not ‘blessed’, so you have to tell the Fire to accept them. Go into settings -> Security settings and check the switch that says “Allow third party apps”
Download and install a file manager. I used ES-File Explorer, which is very popular, but I’ve seen others say “don’t use this it doesn’t work”. I suspect the ‘not working’ has since been fixed. It’s worked fine on 3 devices so far.
Next, pull down the APK’s via the Fire’s Silk Browser. Go to this thread on the XDA Developers forum and click on each of the APK links, and download the files, in order, from top to bottom.
Once they’re downloaded, start up the ES File Explorer, and navigate to the Downloads folder. You’ll see 4 APK’s there. Click on the them from RIGHT TO LEFT (which will install the ‘oldest’ one first, and the Play store last.
After each of the APK’s is installed, launch the Play store, log in with your Google account, and you are all set.

Now that the Fire can install third party apps via the Play store, all we needed to do is install Eventbrite Manager, and log into it with an access-limited login we created just for this event (we’re going to allow general joe schmoes to check people in, and having access to refunds, people’s personal infromation, etc – didn’t seem like a good idea. So a generic Eventbrite login that ONLY allows for checkins was created, and that’s what we logged the tablets into.

I also picked up a handful of desk mounts with really strong gooseneck stalks. Because we’re going to be scanning receipts via the rear camera, the tablet needs to be held off the desk easily.

And we’re done! The Eventbrite Manager app syncs the attendee list whenever it’s connected to the internet. So we can go ahead and check in people super-fast (with a very satisfying BADEEP whenever a successful scan happens), and not have to rely on hotel internet connectivity (which can be notoriously sketchy). At the end of the day, we have a full record of everyone who has checked in and when.

Hack of OnStar Remotelink lets attacker unlock, remote-start, and track cars.

The OwnStar device can detect nearby users of the OnStar RemoteLink application on a mobile phone and can then inject packets into the communication stream to the phone, getting it to give up additional information about the user’s credentials. Those credentials can then be used to gain access to the vehicle’s OnStar account and the full functionality of the OnStar RemoteLink app.

Kamkar says the vulnerability is in the app itself and not the OnStar hardware in GM vehicles. He added that GM and OnStar are working to correct the flaw in the vulnerable mobile application. GM customers who use OnStar can protect themselves for the time being by not using the RemoteLink app.

Good thing I don’t have a GM vehicle that heavily uses OnStar remote services.

Source: ArsTechnica