Year: 2016

Dragging Teletypes Into The 21st Century

May 29, 2016 by 36 Comments

If you are of a certain age you may have worked in an office in the days before the computer revolution, and the chances are that in the corner of your office there would have been a teletype machine. Like a very chunky typewriter with a phone attached, this was an electromechanical serial terminal and modem, and machines like it would have formed the backbone of international commerce in the days before fax, and then email.

Teletypes may have disappeared from the world of trade, but there are a surprising number still in private hands. Enthusiasts collect and restore them, and radio amateurs still use digital modes based on their output. The problem facing today’s teletype owner though is that they are becoming increasingly difficult to interface to a modern computer. The serial port, itself an interface with its early history in the electromechanical world, is now an increasingly rare sight.

[Eric] has a project which addresses the teletype owner’s interfacing woes, he’s created a board with all the necessary level shifters and an Atmega32u2 microcontroller to translate the teletype’s output to USB.

In his design he’s had to solve a few problems related to such an aged interface. Teletypes have a serial output, but it’s not the TTL or RS232 we may be used to. Instead it’s a high-voltage current loop designed to operate electromagnets, so his board has to incorporate an optocoupler to safely isolate the delicate computer circuitry. And once he had the teletype’s output at a safe level he then had to translate its content, teletypes speak 5-bit ITA2 code rather than our slightly newer 7-bit ASCII.

The result though is a successful interface between teletype and computer. The former sees another teletype, while the latter sees a serial terminal. If you have a teletype and wish to try it for yourself, he’s released the source code in a GitHub repository.

Teletypes have featured a few times here at Hackaday over the years. We’ve had one as an SMS client, another that monitors a Twitter feed, and while it’s not strictly a teletype, a close examination of an Olivetti mechanical serial terminal.

Autonomous Truck Teaches Itself To Powerslide

May 29, 2016 by 55 Comments

When you’re a teenager new to the sensations of driving, it seems counterintuitive to “turn into the skid”, but once you’ve got a few winters of driving under your belt, you’re drifting like a pro. We learn by experience, and as it turns out, so does this fully autonomous power-sliding rally truck.

Figuring out how to handle friction-optional roadways is entirely the point of the AutoRally project at Georgia Tech, which puts a seriously teched-up 1/5 scale rally truck through its paces on an outdoor dirt track. Equipped with high-precision IMU, high-resolution GPS, dual front-facing cameras, and Hall-effect sensors on each wheel sampled at 70 Hz, the on-board Quad-core i7 knows exactly where the vehicle is and what the relationship between it and the track is at all times. There’s no external sensing or computing – everything needed to run the track is in the 21 kg truck. The video below shows how the truck navigates the oval track on its own with one simple goal – keep the target speed as close to 8 meters per second as possible. The truck handles the red Georgia clay like a boss, dealing not only with differing surface conditions but also with bright-to-dark lighting transitions. So far the truck only appears to handle an oval track, but our bet is that a more complex track is the next step for the platform.

While we really like the ride-on scale of this autonomous chase vehicle, other than that there haven’t been too many non-corporate self-driving vehicle hacks around here lately. Let’s hope that AutoRally is an indication that the hackers haven’t ceded the field to Google entirely. Why let them have all the fun?

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OzQube-1: A Tiny Australian Satellite

May 29, 2016 by 22 Comments

Over the last couple of decades we have become used to the possibility of launching a satellite into orbit no longer being the exclusive preserve of superpowers. Since the first CubeSats were launched over a decade ago a myriad others have followed, and scarcely a week passes without news of another interesting project in this area.

OzQube-1 is just such a satellite, designed for imaging of the Southern Hemisphere, and it’s the brainchild of Australian [Stuart McAndrew]. He’s posted significant details of its design: it’s a PocketQube, at 50mm cubed, an eighth the volume of a CubeSat, and its main instrument is a 2 megapixel camera with a 25mm lens. Images will be transmitted to earth as slow-scan digital video via the 70cm amateur band, the dipole antenna being made from a springy tape measure which will unfurl upon launch. Attitude control is passive, coming from a magnet aligned to ensure the camera will be pointing Earthwards as it passes over the Southern Hemisphere. The project has a little way to go yet, but working prototypes have been completed and it has a Gofundme campaign under way to help raise the money for a launch.

There are plenty of Cubesat and other small satellite builds to be found on the web, here at Hackaday we’ve covered a significant number of them. Many of them are the fruits of well-funded university departments or other entities with deep pockets, but this one comes from a lone builder from Western Australia. We like that, and we wish OzQube-1 every success!

Find The Source: WiFi Triangulation

May 29, 2016 by 80 Comments

[Michael] was playing with his ESP8266. Occasionally he would notice a WiFi access point come up with, what he described as, “a nasty name”. Perhaps curious about the kind of person who would have this sort of access point, or furious about the tarnishing of his formerly pure airspace, he decided to see if he could locate the router in question.

[Michael] built himself a warwalking machine. His ESP8266 went in along with a GPS module interfaced with a PIC micro controller. It was all housed in an off the shelf case with a keypad and OLED screen. He took his construction for a nice calming war walk around the neighborhood and came home with a nice pile of data to sort through. To save time, he placed the data in a SQL database and did the math using queries. After that it was a quick kludge to put together a website with the Google Maps API and some JavaScript to triangulate the computed results.

Sure enough, the person with the questionable WiFi access point shows up on the map.

Hackaday Prize Entry: An Interface For The Headless Linux System

May 28, 2016 by 17 Comments

Connecting a headless Raspberry Pi to a wireless network can be quite a paradoxical situation. To connect it to the network, you need to open an SSH connection to configure the wireless port. But to do so, you need a network connection in the first place. Of course, you can still get command-line access using a USB-to-UART adapter or the Pi’s ethernet port – if present – but [Arsenijs] worked out a much more convenient solution for his Hackaday Prize entry: The pyLCI Linux Control Interface.

His solution is a software framework written in Python that uses a character display and buttons to make a simple hardware interface. This allows you to configure all important aspects of a Raspberry Pi – or any other Linux SBC – from a tidily organized click-and-scroll menu. [Arsenijs] implemented a whole bunch of useful tools: There’s a network tool to scan and connect to WiFi networks. A systemctl tool that lets you manage the services running on the system, which is especially helpful when you need to restart a stuck service. A partition tool helps with viewing and unmounting mass storage devices. He’s even planning to add a filesystem browser.

With his Open Source project, [Arsenjs] aims to shorten the development time for embedded projects by taking out the efforts of implementing the basic interface functions from scratch. Indeed, there are countless scenarios, where a basic display interface can be of great value. Given the great project documentation and the fact that this can work with virtually any Arduino or Raspberry Pi LCD-pushbutton-hat or shield, we’re sure this is going to be used a lot. Enjoy the video!

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Hand Gestures Play Tetris

May 28, 2016 by 3 Comments

There are reports of a Tetris movie with a sizable budget, and with it come a plentiful amount of questions about how that would work. Who would the characters be? What kind of lines would there be to clear? Whatever the answers, we can all still play the classic game in the meantime. And, thanks to some of the engineering students at Cornell, we could play it without using a controller.

This hack comes from [Bruce Land]’s FPGA design course. The group’s game uses a video camera which outputs a standard NTSC signal and also does some filtering to detect the user. From there, the user can move their hands to different regions of the screen, which controls the movement of the Tetris pieces. This information is sent across GPIO to another FPGA which uses that to then play the game.

This game is done entirely in hardware, making it rather unique. All game dynamics including block generation, movement, and boundary conditions are set in hardware and all of the skin recognition is done in hardware as well. Be sure to check out the video of the students playing the game, and if you’re really into hand gesture-driven fun, you aren’t just limited to Tetris, you can also drive a car.

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Coolest, But Least Secure, Security Device

May 28, 2016 by 51 Comments

[Matikas] apparently forgets to lock the screen on his computer when he gets up to grab a coffee. And he apparently works with a bunch of sharks: “If you don’t [lock it], one of your colleagues will send email to the whole company that you invite them to get some beer (on your bill, of course).” Not saying we haven’t done similar, mind you. Anyway, forgetting to lock your screen in an office environment is serious business.

So [Matikas] built a great system that remotely types the keystrokes to lock his screen, or unlock it with his password. An off-the-shelf 433 MHz keyfob is connected to an Arduino micro that simulates a keyboard attached to his computer. It’s a simple system, but it’s a great effect. (See the video demo, below.)

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