You’ll Never See the End of This Project

…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!

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, …read more

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Sharpest Color CRT Display is Monochrome Plus a Trick

I recently came across the most peculiar way to make a color CRT monitor. More than a few oscilloscopes have found their way on to my bench over the years, but I was particularly struck with a find from eBay. A quick look at the display reveals something a little alien. The sharpness is fantastic: each pixel is a perfect, uniform-colored little dot, a feat unequaled even by today’s best LCDs. The designers seem to have chosen a somewhat odd set of pastels for the UI though, and if you move your head just right, you can catch flashes of …read more

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ULX3S: An Open-Source Lattice ECP5 FPGA PCB

The hackers over at Radiona.org, a Zagreb Makerspace, have been hard at work designing the ULX3S, an open-source development board for LATTICE ECP5 FPGAs. This board might help make 2019 the Year of the Hacker FPGA, whose occurrence has been predicted once again after not quite materializing in 2018. Even a quick look at the board and the open-source development surrounding it hints that this time might be different.

The ULX3S was developed primarily as an educational tool for undergraduate-level digital logic classes. As such, it falls into the “kitchen sink” category of FPGA boards, which include a comprehensive suite …read more

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DIY Guided Telescope Mount Tracks Like a Barn Door

Astrophotography is an expensive hobby. When assembling even a basic setup consisting of a telescope, camera, guiding equipment and mount, you can easily end up with several thousand dollars worth of gear. To reduce the monetary sting a little, [td0g] has come up with an innovative homebrew mount and guiding solution that could be assembled by almost any dedicated amateur, with the parts cost estimated around $100. The accuracy required to obtain high-quality astrophotographs is quite demanding, so we’re impressed with what he’s been able to achieve on a limited budget.

The inspiration for this design comes from an incredibly …read more

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Electromagnetic 7-Segment Display Easy on the Eyes AND the Ears

We love electromagnetic displays: take the modern look of a digital readout, combine with the low-tech coil mechanism that you theoretically could create yourself, add a dash of random clacking sounds, and what’s not to like? Evidently, [Nicolas Kruse] shares our affection for these displays, because he’s taken it beyond theory and created a 7-segment magnetically-actuated display from scratch.

The display is 3D-printed, as you would expect these days. Each segment contains a small neodymium magnet, and each coil a 1 mm iron core for flux concentration. The coils are driven with a 1.6 A peak current, causing the segments …read more

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Program This Badge in Lisp

This hardware badge is a computer programmed with Lisp. You can write your own programs right on the badge using the built-in keyboard, as long as you know Lisp.

If there’s one thing we really like to see, it’s people advancing their own projects based on inspiration from others. The Lisp Badge by [David Johnson-Davies] is a perfect example. With an interface inspired by [Voja Antonic’s] hardware design for the 2018 Hackaday Belgrade Conference Badge, this version is an upgrade of an earlier single-board Lisp machine, now sporting an integrated keyboard.

Unlike the Belgrade badge, which is programmed in BASIC, …read more

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Peering Into a Running Brain: SDRAM Refresh Analyzed from Userspace

Over on the Cloudflare blog, [Marek] found himself wondering about computer memory, as we all sometimes do. Specifically, he pondered if he could detect the refresh of his SDRAM from within a running program. We’re probably not ruining the surprise by telling you that the answer is yes — with a little more than 100 lines of C and help from our old friend the Fast Fourier Transform (FFT), [Marek] was able to detect SDRAM refresh cycles every 7818.6 ns, lining right up with the expected result.

The “D” in SDRAM stands for dynamic, meaning that unless periodically refreshed by …read more

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An IoT Christmas Tree You’re Invited to Control

We love IoT gadgets, but are occasionally concerned that they might allow access to the wrong kind of hacker. In this case, [Kevin] has created an IoT tree that allows anyone to control the pattern of lights, and he’s invited you to do so!

We played with the tree a bit, and the web interface is fairly powerful. For each LED, you can select either a random color or a keyframe-defined pattern. For the keyframe LEDs, you can create a number of “keyframes”, each of which is defined by a color and a transition, which can be either linear, quarter …read more

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IPv6 Christmas Display Uses 75 Internet’s Worth of Addresses

We’ve seen internet-enabled holiday displays before, and we know IPv6 offers much more space than the older IPv4 addressing scheme that most of us still use today, but the two have never been more spectacularly demonstrated than at jinglepings.com. The live video stream shows an Internet-connected Christmas tree and an LED display wall that you can control by sending IPv6 ICMP echo request messages, more commonly known as pings.

Reading the page, you quickly parse the fact that there are three ways to control the tree. First, you can type a message in the box and press send – this …read more

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Tired of Killing Houseplants? Try Using WiFi.

Here at Hackaday, we have to admit to neglecting a few houseplants in our time. Let’s face it… a cold, hard, thinking machine can care for our green friends better than you can. Why not team up? [cabuu]’s WiFi-enabled soil moisture sensor will do the trick in case you, too, want happy plants.

This is one of those projects which would have been much more difficult even five years ago, and really shows how lucky we are to have accessible technology at our fingertips. It’s conveniently constructed from off-the-shelf electronics modules, and nestled inside a 3D-printed case. The design is …read more

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