Operating radio satellites for fun and profit
For the ham/amateur radio operator, there are three interesting satellites in low earth orbit. Okay, two satellites and one International Space Station (ISS). Anyone with an amateur radio and an FCC license can operate these objects from the surface of the Earth. No complicated equipment is needed and you can often use a simple "whip" antenna attached to your handheld ham radio. Five watts of power is typically sufficient to reach the orbiting objects, since it's a clear line of sight to space.
There are two forms of "information" you can exchange with these satellites -- voice, and packets. With a $30 Baofeng Radio you can operate voice, and with a bit more money ($250), you can get a radio with APRS packet modems.
APRS packet radio is by far the easiest, and the only real way to operate through the ISS. Send a packet on 145.825Mhz, and wait for it to be repeated over your continent by the 5watt digipeater installed in the station. Feedback is almost immediate as you typically see your callsign and position pop up on your radio a second later. You'll also see callsigns from other stations doing what you're doing, only they'll be as far as 1000 miles away. For extra credit, send an APRS message to callsign "SMSGTE" including a phone number and a short SMS message. Tell the recipient they're being contacted via the International Space Station. It's a cool bar trick.
The second of three radio satellites is "Parkinsons SAT," aka "PSAT", aka "NO-84." It's operated in exactly the same manner as the ISS, though, be warned, it only operates at 0.25 watts, assuming it has a charged battery. A whip antenna might work, but get a better after market antenna like a rollup jpole antenna from EBay ($25).
The third of three satellites is "Saudisat," aka "SO-50." This is your voice satellite. It's a bit trickier in that you transmit on 145.850Mhz (same as above two objects), but you also need to continuously transmit a subaudible PL tone of 67.0Hz for it to recognize and repeat your voice signal. Due to a very limited power budget, it must be first "activated" by a two second transmission on 145.850Mhz with a PL tone of 74.4Hz. At that point, if it has power, it will listen on 145.850Mhz (with 67Hz PL now), and repeat back to earth on 436.795Mhz. I use two radios for this one, or just one radio with "dual-band." This satellite is often very busy with people exchanging call signs and nothing more, mostly so they can say they contacted a far-off station. The radiation cones on these things is several thousand miles so it's possible to talk to anyone on your continent.
To operate any of these, you need to know when they're in your sky, and at least 20 degrees off the horizon. Straight up (90 degrees) is always best, and they typically cross your sky in 10 minutes, giving you a five minute window to communicate. Get the satellite tracking info here: https://www.n2yo.com/?s=25544|40654|27607 . Take note of maximum height which is degrees off the horizon (your antenna angle), and maximum "azimuth" which is a fancy way of saying which way you should point the low end of your antenna (North/South/East/West). Unlike terrestrial communications, when you're talking to space, you hold your antenna somewhat horizontally. Did I mention getting a compass for this? Get one, and draw a compass rose on the ground for next time.
While you're there, send an APRS message to KM6LYW so I know you read this :).
Amateur radio in the information agecraiger
When I mention HAM radio, most people are reminded of the orange glow of vacuum tubes, incessant static, and a quiet nerd staring diligently at a desktop microphone. While this was true last century, it's quite a different story today. That HAM radio now fits in the palm of your hand. It's packed with modern computing power, GPS, digital modems and radio technology that still runs the space program. Modern HAM radios aren't wildly different than the cellular/mobile radio you have in your pocket. Today's HAM radios send SMS messages, email, and allow you to talk to anyone in your state using freely available repeater systems. The key difference is that HAM radio doesn't come with a huge bill at the end of the month and horrible customer service. HAM radio usage is absolutely free, in multiple senses of the word. With a $30 investment, you can start talking, with $200 you can go digital. The perceived barrier to entry is the "FCC Exam" required for a license. A ninety minute youtube video, a few practice tests (hamstudy.org) and fifteen dollars will give you all the interesting information you need to pass the simple thirty-five question test with 75% or better. HAM radio has seen a resurgence with the "prepper community" as it's a proven and resilient communication system. Most of the infrastructure is solar powered and off-grid. Cellular networks rely on fragile infrastructure -- even on a good day, you might not have cellular signals in your location. HAM radio is a free and easy supplement to your cell phone, why not have both, knowing that if things get bad, you'll at least have one? HAM Radio -- it worked then, and it's even better now!
The state of the Linux desktopcraiger
The Linux desktop is in shambles. I don't mean to be critical of all the hard work in this space, but it's getting worse, not better. It peaked in the later stages of KDE4 and Unity. Now KDE5 isn't useable and Canonical indicated they're no longer developing Unity. I'll be the first to admit I was a KDE fan, and I'd highly recommend Unity to family and friends for more casual use. KDE5 completely burned down KDE4 and started over with the new QT5 toolkit and Plasma desktop. At first glance, it looks a lot like KDE4, until you try to customize something the way you had it on KDE4 -- it's not possible. Kwin crashes every hour, but, luckily development went into restarting it as quickly as possible after it crashes, so, it's more of a "blink." Don't like the icon spacing on the desktop? Want smaller taskbar and desktop icon fonts? Were window shadows important to you? Did any of your favorite apps port to QT5? How does it feel to want? KDE5 misses the mark on these seemingly trivial features, but there are so many, they all add up to an unusable desktop. I refuse to migrate, so I'm stuck on KDE4 and an old version of Ubuntu. At least LTS releases last seven years.
So what did we learn? Taking a radical new approach to your project is natural, inevitable and fun. Just keep in mind in the IT industry, if you make a change, never leave your users with less than what they had before. If you take a new direction, don't take away seemingly trivial features, or people will not follow you. You'll be developing a hot new technology that nobody wants, because it doesn't give them the functionality they had before. Also, "clever" is not "better." Many clever changes are for the sake of being clever, with a huge wake of unintended consequences, with stability often being the first to go. Flexibility and ease of use are two qualities which tend to vary inversely. Know your audience in this regard, and cater to one, but not both, or you'll lose both. Linux could/should boil down to two leading desktops in the end.
For completeness, I've tried all the "new stuff" out there like Cinnamon, xfce, Gnome, Pantheon, and ElementaryOS, the majority of which are a fresh coat of paint on the tired Gnome/gtk desktop.
So what do you use and why?
Prevent ROKU auto-updates, ads craiger
I normally prefer appliance-like-things to auto update themselves with the latest patches. Who doens't like automatic features, greater stability and security patches? Unfortunately not all updates are good, and in the case of the latest patch from ROKU, show-stopper (pardon the pun) bugs were introduced. For the average user, there is nothing you can do about it. You do not control the change management process, and the terms of service indicate they control the content on the device, not you. You do, however, control the network to which their device is attached. Disconnecting the device from the internet is one option, but you throw out youtube, netflix, and other streaming content with the bath water. A more surgical network configuration is in order. You probably have a nice wifi bridge at home with firewawall and dnsmasq capabilities. If you don't, get a device that supports DD-WRT firmware or anything that lets you setup dnsmasq. Don't like auto updates? simply add "address=/.sw.roku.com/127.0.0.1" to your dnsmasq configuration. Dont' like roku banner ads? simply add "address=/cloudservices.roku.com/127.0.0.1" to your dnsmasq configuration. See below if you don't like Kindle ads, it's really that simple. Sure it's difficult to figure out which servers to ice, but that's where tcpdump comes in -- run it on your Linux router and you can see exactly how all these little devices "phone home."
Hacking the Amazon Kindle craiger
If you don't have a paper-white e-reader, stop reading this and get one now. I retired my Kobo in favor of a new Amazon Kindle Paper White (model3). Like my Kobo, the Kindle runs Linux. There's always a technocratic battle between hackers and manufacturers to jailbreak devices -- the Kindle is no exception. The most recent Kindle firmware makes this problematic, requiring a hardware serial port adapter to acquire root on the device. No worries, my primary goal was to get rid of the annoying ads on the home screen and the screen-saver. We can accomplish this without rooting the device, and simply make a single change in flash ram and tweak our home router. First, plugin the kindle to your (preferably Linux) pc, then rename the file /system/.assets to /system/.assets.off. Enable airplane mode, then reboot the device. No ads! Unfortunately, disabling airplane mode brings back ads, which brings us to step 2: Modify your (preferably Linux) wifi router so your Kindle cannot reach the Amazon ad servers. If your router supports DNSMasq (most do, including DDWRT), simply ice this hostname: "adpublisher.s3.amazonaws.com". On a DDWRT router, the DNS masq settings are in Services->Services:DNSmasq. Add the line "address=/adpublisher.s3.amazonaws.com/127.0.0.1". Now you can enable wifi, access the Kindle store, and enjoy ad-free reading. It deserves noting that a less interesting, and more expensive way to accomplish this is to simply go to amazon.com and upgrade your device for US$30 to disable "special promotions," but where's the fun in that?
Chromium Browser better or worse? craiger
I'm rarely critical of an opensource project, but recent changes to Chrome, in my opinion have been misguided. As software developers, we should try to make sure every change is in support of the design requirements, not just implement something because we think it's clever. With something as big as Chrome, the wake of unintended consequences for poorly conceived changes is overwhelming. Chromium developers have switched away from the GTK gui, and are consolidating their platform code base -- both are admirable tasks. In the process, they're actually hard-coding Windows "features" into Linux/Mac/Android builds. This is a great way to lose those user communities. These people don't use Microsoft products for a reason (the reason is irrelevant). I, and others, are now rebuilding chromium-browser with a set of patches to revert all the microsoft-isms they're hard coding into chrome. For example, if you grab the scrollbar with the mouse, and deviate an inch left or right, the scroll-bar suddenly snaps back to it's original position. I realize Microsoft users have spent decades learning to cope with this (defective-by) design, but to the rest of the world, the behavior staggers the imagination. So if the Chromium developers ignore your bugs, or you'd like to regress unfortunate changes to your favorite software, you'll find it's rather easy to patch and rebuild debs. I use this example for Ubuntu to rebuild Chrome, which takes about four hours, then share the resulting debs with friends. Even if you're not a developer, this is a gentle way to familiarize yourself with the gcc/autoconf build process.
SUSECON 2015 in Amsterdam craiger
SUSECON is in the great port city of Amsterdam this year. I'll be presenting a topic and lurking by the Hewlett Packard Enterprise booth. Please come by and say hi!
Banana Pro! Low power home server. craiger
Normally I wouldn't plug products here, but I've since upgraded the venerable Raspberry Pi to a "Banana Pro." Think of it as an evolutionary process. Every feature of the Raspberry has seen an iterative upgrade. We've gone from A6 to A7 arm cpu's, doubled the memory, integrated wifi, and, most importantly, added a SATA port so you can attach a REAL disc drive! It's likely your favorite Linux distribution is available for the Banana Pro, and I happen to be using LUbuntu (light version of Ubuntu for ARM). A Banana Pro kit can be had on Amazon for $US70, and you can get a solid state disc for $US40. While you're on Amazon, get the double-decker acrylic case to hold both the Banana and the 2.5" SSD drive. You can physically see and use my Banana Pro at http://wx.sidrraglider.com. It's currently pulling weather station duty, but I expect it to do much more now that we have a real disc drive. The old RaspberryPi couldn't reliably store data on the SD flash card (I used ramdiscs instead), but the BananaPro has no such limitation.
Two wifi routers in one house with Linux firmware. craiger
Is your house long? Longer than the typical range of an FCC licensed wifi router? Extend your network! While it's possible to bridge two access-points wirelessly, I suggest running a cat6 cable the length of your house. Plug one end into your "official" wifi router, and plug the other end into a wifi slave. Use channels 1, 6 or 11 for proper frequency isolation. The slave router needs some tweaking so it doesn't compete with your master router. Simply disable it's dhcp server, change it's IP address (from 192.168.1.1 to 192.168.1.2 for example), set the SSID to be the same as the master's, and enter a WEP/WPA security passphrase that's the same as the master's. Your clients will automatically use whichever wifi router is "closer." Your family wont have to change a thing on their devices, they'll just notice stronger signals throughout your house. If you're like me, you have an old Linksys linux-based router in your office as the master, and a cheap TP-Link slave router behind your media center at the other end of your house. Your TV, Roku, PS4, and other devices have rj45 network connections, so hardwire them to your slave router, and let all your phones and tablets roam between your two wifi hot spots (they'll see only one network name). If you use DD-WRT as your open source router firmware (which I do), you can even use the "WAN" port on the back of the slave as a switch port, giving you five ports to use behind your media center.
Plex media servercraiger
Upnp/dlna has been around for ages, and nobody has come up with a working client server model that is easy to use. Enter "Plex." This is a best-of-breed technology company that implements both dlna servers and clients. Get a couple of Western Digital Red 4TB drives, make them a raid1 mirror, put them in an Ubunutu PC, and "apt-get install plexmediaserver". Visit localhost:32400 and configure the media server, including the location of all your content. On your favorite bluray player, roku, or smart tv, get the "Plex" app. Ideally encode all your DVD's per the handbrake article below, but if your movies don't play directly on your device, don't worry, plexmedia server will detect that and transcode the video stream on the fly. So it effectively works with all media types and codecs. The Plex app looks and works exactly like Netflix, so if you like that UI, you'll like Plex.
Spin down noisy, unused drives craiger
If you have an audio workstation, or just want to keep your office quiet, nothing screws things up like noisey disks spinning, often needlessly. If you have a big "backup" drive along with your primary root volume, you can spin it down when not in use. "hdparm -S 20" used to tell drive firmwares to spin themsleves down if there was no access over five minutes -- modern drive firmware ignores this directive these days. Since we're using Linux, this script "spindown.sh" will accomplish the same thing. simply edit the top of the script to include the wwn names of the drives you wish to monitor, then setup a run frequency in cron (say every 30 minutes). Idle drives will be silenced, then spin themselves up on demand. The jbd journal on ext4 filesystems normally puts timestamps on drives at a prescribed frequency -- I was about to combat this issue but noticed the drives stay spun down despite this. It requires a genuine filesystem access to wake them up.
Handbrake video encoding craiger
HandBrakeCLI -2 -T --cfr -B 320,192 -q 18.6 -t $TITLENUM --gain=+5,+5 --drc=1.5,1.5 -a 1,1 -E ffac3,ffaac --mixdown 5point1,dpl2 --preset="High Profile" -i $INPUT -o $FILENAME
While this isn't open source, it's super easy to rip your dvd collection into a NAS filled with mp4 videos and vend them with Plexmediaserver, or any DLNA server. The above Handbrake syntax creates a dvd-quality copy with 5.1 surround sound which is compatible with a Roku device, and most other DLNA TV and BluRay players. Audio quality is reduced a bit to save space, yet hard to notice. Video is reduced to 25% of the original space, and I can't personally see the difference. A 2-hour dvd fits nicely into 1.5G. Why is this important? An increasing number of BluRay players implement Cinavia copy protection which prevents you from streaming legal copies of your dvds. These defective-by-design Blu Ray players should not be used for this purpose, or arguably any purpose. Instead, use your TV's dlna client, or better yet, get a Roku3!
Web hosting easier than ever craiger
Anyone with $11.50 and a connection to http://omnis.org can buy a domain these days, even me. Let http://dreamhost.com host the DNS records, and point an MX record and google's smtp server and you have a complete IT infrastructure for less than $50/year. How much time and money does it take to get your company to do something similar? This used to be a lot harder! Now anyone can do it. This means we're finally doing things right.
Using existing web templates? craiger
I must admit this is the first time I've used an existing "free" web template found-on-internet. Back in the day we started with an empty vi editor and started typing until there was a web page. A few minutes in gimp and you had graphics. While you should still use vi and gimp, you can get a head start by picking out a free html/css template, with minimal amounts of javash*t obfuscating your site. http://freewebsitetemplates.com