You’ll Never See The End Of This Project

January 17, 2019 by Ted Yapo 26 Comments

…theoretically, anyway. When [Quinn] lucked into a bunch of 5 mm red LEDs and a tube of 74LS164 shift registers, a project sprang to mind: “The Forever Number,” a pseudo-random number generator with a period longer than the age of the universe. Of course, the components used will fail long before the sequence repeats, but who cares, this thing looks awesome!

Check out the gorgeous wire-wrapping job!

The core of the project is a 242-bit linear-feedback shift register (LFSR) constructed from (31) 74LS164’s. An XOR gate and inverter computes the next bit of the sequence by XNOR’ing two feedback bits taken from taps on the register, and this bit is then fed into bit zero. Depending on which feedback taps are chosen, the output sequence will repeat after some number of clock cycles, with special sets of feedback taps giving maximal lengths of 2^N – 1, where N is the register length. We’ll just note here that 2²⁴² is a BIG number.

The output of the LFSR is displayed on a 22×11 array of LEDs, with the resulting patterns reminiscent of retro supercomputers both real and fictional, such as the WOPR from the movie “War Games,” or the CM2 from Thinking Machines.

The clock for this massive shift register comes from – wait for it – a 555 timer. A potentiometer allows adjustment of the clock frequency from 0.5 to 20 Hz, and some extra gates from the XOR and inverter ICs serve as clock distribution buffers.

We especially love the construction on this one. Each connection is meticulously wire-wrapped point-to-point on the back of the board, a relic originally intended for an Intel SBC 80/10 system. This type of board comes with integrated DIP sockets on the front and wire-wrap pins on the back, making connections very convenient. That’s right, not a drop of solder was used on the board.

You can see 11 seconds of the pattern in the video after the break. We’re glad [Quinn] didn’t film the entire sequence, which would have taken some 22,410,541,156,499,040,202,730,815,585,272,939,064,275,544, 100,401,052,233,911,798,596 years (assuming a 5 Hz clock and using taps on bits 241 and 171 ).

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Arduino Hunts (and Sees) The Wumpus

January 15, 2019 by Tom Nardi 13 Comments

For anyone who’s been fiddling around with computers since the days before VGA, “Hunt the Wumpus” probably brings back fond memories. Developed in 1973, this text game has you move around a system of caves searching for the foul-smelling Wumpus, a vile creature which you must dispatch with your trusty bow and arrow. Some consider it to be one of the very first survival horror games ever developed, a predecessor to the Resident Evil franchise as well as the video game version of Hannah Montana: The Movie.

If the concept of “Hunt the Wumpus” sounds interesting to you, but you just can’t get over the whole text adventure thing, you may be in luck. [Benjamin Faure] has developed a semi-graphical version of the classic horror title which might better appeal to your 21st century tastes. Running on an Arduino Mega 2560 with graphics displayed on a 8 x 8 LED matrix, it’s not exactly DOOM; but at least you won’t have to type everything out.

For his handheld version of “Hunt the Wumpus”, [Benjamin] 3D printed a nice enclosure and adorned it with labels and instructions that look like tiny scrolls, a neat touch for a game that’s so old contemporary players would have called Zork a “next gen” game. While playing you can see where you’ve been and where you are currently thanks to illuminated dots on the MAX7219 display, and there are LEDs to warn you of your proximity to bottomless pits and the Wumpus itself. There’s even a piezo speaker that will chirp when a bat is nearby, which is important as they have a tendency to ruin your day by carrying you away to a random location in the cave.

Most of the game looks like an advanced version of Snake, but [Benjamin] did go through the trouble of adding some rudimentary animations and sound effects that play during specific parts of the game. When you shoot your arrow or get carried away by a bat, you’ll see a “cutscene” of sorts on the LED display. It’s a fairly simple effect, but helps break up the otherwise fairly spartan graphics and might just be enough to keep a youngins’ attention.

If you subtract a dimension, this project is reminiscent of the 1D dungeon crawler we covered last year. But if even one dimension is too many, you could always run the text version of “Hunt the Wumpus“ on your trusty Arduino.

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CNC Turns A Single PCB Into Origami Hemisphere

January 13, 2019 by Dan Maloney 8 Comments

Trying to make a hemispherical surface out of a PCB is no easy feat. Trying to do that and make the result a working circuit is even harder. Doing it with one solid piece of FR4 seems impossible, right?

Not so much. [brainsmoke] came up with a clever way to make foldable, working PCBs that can be formed into hemispheres. The inspiration for this came from a larger project that resulted in a 32-cm diameter LED-studded sphere, which a friend thought would make a swell necklace if it was scaled down. That larger sphere was made somewhat like a PCB soccer ball, with individual panels soldered together. [brainsmoke] didn’t relish juggling dozens of tiny PCBs to make a necklace-sized version, so the unfolded pattern for half a deltoidal hexecontahedron was laid out as one piece on single-sided FR4. The etched boards were then cut out on a CNC mill, with the joints between the panels cut as V-grooves from the rear of the board. By leaving just enough material to act as a live hinge, [brainsmoke] was able to fold the pattern up into a hemisphere while leaving the traces intact. The process was fussy and resulted in a lot of broken FR4 and traces, but with practice and the use of thicker board material and heavier copper, the hemisphere came together. The video below shows the final product

This objet d’art is [brainsmoke]’s entry in the Circuit Sculpture Contest, which ~~is just wrapping up~~ wrapped up last week. We can’t wait to share some of the cool things people came up with in this contest, which really seemed to get the creative juices flowing.

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Hot Glue Makes These Segments Glow

January 13, 2019 by Jenny List 14 Comments

It’s safe to say that hot-melt glue is a staple of the projects we see here at Hackaday. There won’t be many readers who don’t have a glue gun, and a blob of the sticky stuff will secure many a project. But it’s not so often we see it used as an integral component for a property other than its stickiness, so [DusteD]’s reaction timer project is interesting for having hot glue as a translucent light guide and diffuser for its LED seven-segment display.

The timer is simple enough, being driven by an Arduino board, while the display is pre-formed into the 3D-printed case. The hot glue fills the enclosures behind each segment, and after several experiments it was found that the best filling method was from behind against a piece of Kapton tape. The LEDs were wired into a common cathode array, and along with the arcade-style button and the Arduino the whole fitted neatly in the box. You can see the result in action in the video below the break.

Of course, this display is unusual for its use of hot glue, but not unique. We’ve seen a different take on a hot glue light pipe display before.

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Addressable 7-Segment Displays May Make Multiplexing A Thing Of The Past

January 12, 2019 by Dan Maloney 52 Comments

[Sean Hodgins] has a knack for coming up with simple solutions that can make a big difference, but this is one of those “Why didn’t I think of that?” things: addressable seven-segment LED displays.

[Sean]’s design is basically a merging of everyone’s favorite Neopixel RGB LED driver with the ubiquitous seven-segment display. The WS2811 addressable RGB driver chip doesn’t necessarily have to drive three different color LEDs – it can drive three segments of the same display. With three of the chips on a single board, all seven segments plus the decimal point of a display can be controlled over a single data line. No more shift registers, no more multiplexing. And as a nice touch, individual displays can be ganged together with connectors on the back of each module. [Sean] has some code to support the display but is looking for someone to build a standalone library for it, so you might want to pitch in. Yes, he plans to sell the boards in his shop, but as with all his projects, this one is open source and everything you need to build your own is up on GitHub. The brief video below shows a few daisy-chained displays in action.

Like many of [Sean]’s designs, including this Arduino rapid design board, this is a simple way to get a tedious job done, and it wrings a lot of functionality from a single IO pin.

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Visual Airplane Tracker Runs On Pi

January 11, 2019 by Richard Baguley No comments

As no doubt is the case with many readers, there is a Raspberry Pi running in the yard near where this is being written that tracks airplanes, listening into the ADS-B radio broadcasts that they send and uploading the data to a sharing service. This device lacks the blinky LEDs that hacking custom states it should have, though. This project from [xy72y5e] would be a great way to deal with that problem: they used a Unicorn hat to create a simple map of local airplanes. This shows the location and track of aircraft in the area on the 8 by 8 RGB LED matrix of the Unicorn Hat.

While the device here maps local planes from their radio fixes, the code that [xy72y5e] published works with the api of ADSBExchange, a site that shares flight data. This means that the map can be easily set to show air traffic at a different location to the device itself. And it wouldn’t be that difficult to alter this to show the locally detected planes, as [xy72y5e] has published the full Python code that creates the map. This would also go well with some of the other airplane tracking hacks that we’ve seen recently, such as the planespotter destination tracker or tracking airplanes by radar reflections…

[Via Reddit]

WiFi Remote Control Those Cheap LED Strips With An ESP8266 Passthrough

January 9, 2019 by Jenny List 23 Comments

The explosion of cheap LED lighting products has given a never-ending array of opportunities for the resourceful hacker. A few dollars can secure strings of colourful illumination, but without further expenditure they lack the extra utility of electronic control. This is something that [Albert David has addressed] with his simple ESP8266-based WiFi switcher that he’s added to a string of USB-powered LEDs, and he’s neatly mounted the ESP-12 module it used atop a USB plug.

The circuitry is pretty straightforward, with only a couple of I/O lines being used. A transistor takes care of the heavy lifting, and the software comes courtesy of the Tasmota firmware for Sonoff (and similar) devices. We suspect with this economy of connection, the same task could be achieved even with the limited resources provided by the lesser ESP-01 module.

There was a time not so long ago when performing a task such as controlling a light over a wireless network involved significant cost, power, and complexity. In the nearly five years since we reported on the arrival of the ESP8266 we have progressed to the point at which that task is a simple project using commodity components, and that represents something of a miracle.