So far in this brief series on in-band signaling, we looked at two of the common methods of providing control signals along with the main content of a transmission: DTMF for Touch-Tone dialing, and coded-squelch systems for two-way radio. For this installment, we’ll look at something that far fewer people have ever used, but almost everyone has heard: Quindar tones.
The Raspberry Pi is an incredibly versatile computing platform, particularly when it comes to embedded applications. They’re used in all kinds of security and monitoring projects to take still shots over time, or record video footage for later review. It’s remarkably easy to do, and there’s a wide variety of tools available to get the job done.
However, if you need live video with as little latency as possible, things get more difficult. I was building a remotely controlled vehicle that uses the cellular data network for communication. Minimizing latency was key to making the vehicle easy to drive. Thus I set sail for the nearest search engine and begun researching my problem.
My first approach to the challenge was the venerable VLC Media Player. Initial experiments were sadly fraught with issues. Getting the software to recognize the webcam plugged into my Pi Zero took forever, and when I did get eventually get the stream up and running, it was far too laggy to be useful. Streaming over WiFi and waving my hands in front of the camera showed I had a delay of at least two or three seconds. While I could have possibly optimized it further, I decided to move on and try to find something a little more lightweight.
[Frank] was lucky enough to score a bucket wheel excavator LEGO set as a birthday present, and we won’t lie – we’re jealous. However, out of the box, the kit is somewhat limited; there is only one motor to animate the entire machine and it can’t be fully remote controlled. But don’t worry — [Frank] set out to change that (Google Translation).
The first part of the build was to add motors to control the different functions of the excavator. One motor was added for each of the two tracks to allow the machine to drive forwards, backwards, and turn. Two more motors were added to raise and lower the digging buckets, and spin the tower. Finally, the original motor was left in place to turn the conveyor.
With that done, [Frank] then used a Raspberry Pi 3 to control all the hardware, being sure to house the new electronics in LEGO for an original look. The Raspberry Pi might be a lot of muscle to simply control a few motors, but it made it quick and easy for [Frank] to implement a Wiimote as a controller over Bluetooth. You can check out a couple demo videos in his most recent update.
It’s a great project, and we’d love to see the Raspberry Pi put to good use by allowing control over the Internet so we can dig in the sand over lunch breaks. We’ve seen some great LEGO hacks before, like this method of modifying cheap gear motors to work with LEGO parts.
It’s May, and you know what that means: we’re winding down from a worldwide celebration of the worker, pollen is everywhere, Hackaday readers in the southern hemisphere are somehow offended, and somewhere, someone is finishing up a remote-controlled snow blower build.
In this nine-part, two-hour-long video series, [Dave] covers the planning and fabrication of one of the most coveted of all cold weather yard instruments. It’s a remote-controlled snow blower. Just think: instead of bundling up to go blow the driveway off, [Dave] can get all the snow off his driveway from the comfort of his living room window. Sure, it may not sound like a big deal now that it’s Crocs & Socks weather, but this is going to be a great invention in seven or eight months.
This snow blower robot is built around two motors taken from an electric wheelchair. Most snowblowers already have tracks, so the ever-important traction for this build is already taken care of. A linear actuator takes care of the angle of the ‘scoop’, and a clever confabulation of bicycle sprockets, chain, and a motor allows the ‘chute’ of the snowblower to be pointed in any direction. The electronics are simple enough – a normal, off-the-shelf RC transmitter and receiver handles the wireless communication while an Arduino takes those signals and turns them into something the relays and motors understand.
This is one of the better build vlogs we’ve seen. There are nine parts to this build, we’ve included the final, wrapup video below.
[Pen Test Partners] have found some really scary vulnerabilities in AGA range cookers. They are connected by SMS by which a mobile app sends an unauthenticated SMS to the AGA to give it commands for instance preheat the oven, You can also just tell your AGA to turn everything on at once.
The problem is with the web interface; it allows an attacker to check if a user’s cell phone is already registered, allowing for a slow but effective enumeration attack. Once the attacker finds a registered device, all they need to do is send an SMS, as messages are not authenticated by the cooker, neither is the SIM card set up to send the messages validated when registered.
This is quite disturbing, What if someone left a tea towel on the hob or some other flammable material before leaving for work, only to come back to a pile of ashes? This is a six-gazillion BTU stove and oven, after all. It just seems the more connected we are in this digital age the more we end up vulnerable to attacks, companies seem too busy trying to push their products out the door to do simple security checks.
Before disclosing the vulnerability, [Pen Test Partners] tried to contact AGA through Twitter and ended up being blocked. They phoned around trying to get in contact with someone who even knew what IoT or security meant. This took some time but finally they managed to get through to someone from the technical support. Hopefully AGA will roll out some updates soon. The company’s reluctance to do something about this security issue does highlight how sometimes disclosure may not be enough.
[Via Pen Test Partners]
A few weeks ago we covered a (probably) bogus post about controlling a TV with the IR from a flame. That got us thinking about what the real origin of the remote control was. We knew a story about the 38 kHz frequency commonly used to modulate the IR. We’ve heard that it was from sonar crystals used in earlier sonic versions of remotes. Was that true? Or just an urban myth? We set out to find out.
Surprise! Remotes are Old!
If you are a younger reader, you might assume TVs have always had remotes. But for many of us, remotes seem like a new invention. If you grew up in the middle part of the last century it is a good bet you were your dad’s idea of a remote control: “Get up and turn the channel!” Turns out remotes have been around for a long time, though. They just weren’t common for a long time.
If you really want to stretch back, [Oliver Lodge] used a radio to move a beam of light in 1894. In 1896, [Marconi] and some others made a bell ring by remote control. [Tesla] famously showed a radio-controlled boat in 1898. But none of these were really remote controls like we think of for a television.
Of course, TV wouldn’t be around for a while, but by the 1930’s many radio manufacturers had wired remotes for radios. People didn’t like the wires, so Philco introduced the Mystery Control in 1939. This used digital pulse coding and a radio transmitter. That’s a fancy way of saying it had a dial like an old telephone. As far as we can tell, this was the first wireless remote for a piece of consumer equipment.
We recently published an article where someone apparently controlled their TV by simulating a remote with merely a lighter and a sheet of paper. The paper had a barcode like cutout for a supposed “Universal Standby Signal”. The video rightfully attracted a substantial crowd, some awestruck by its simplicity, others sceptical about its claims.
Coming from some generic “Viral Life Hack” production house, the characteristic blare of background music, more suited to an underground rave than a technical video, certainly did not do it any favours. As any moderately experienced campaigner would know, modern televisions and remotes have been carefully engineered to prevent such mishaps. Many of us at Hackaday, were under the impression that it would take something slightly more sophisticated than a fluorescent-bodied lighter and a crisp sheet of A4 to deceive the system. So we tested it out. Our verdict? Unlikely, but not impossible. (And we’re pretty sure that the video is a fake either way.) But enough speculation, we’re here to do science.