Posts

Featured Post

An Electric Jellyfish For Androids

-
Image
We have to admit, we didn’t know that we wanted a desktop electric jellyfish until seeing [likeablob]’s Denki-Kurage , but it’s one of those projects that just fills a need so perfectly. The need being, of course, to have a Bladerunner-inspired electric animal on your desk, as well as having a great simple application for that Cheap Yellow Display (CYD) that you impulse purchased two years ago. Maybe we’re projecting a little bit, but you should absolutely check this project out if you’re interested in doing anything with one of the CYDs . They are a perfect little experimentation platform, with a touchscreen, an ESP32, USB, and an SD card socket: everything you need to build a fun desktop control panel project that speaks either Bluetooth or WiFi. We love [likeablob]’s aesthetic here. The wireframe graphics, the retro-cyber fonts in the configuration mode, and even the ability to change the strength of the current that the electric jellyfish is swimming against make this look so co...
Post a Comment
Get this one»

Analog Video From an 8-Bit Microcontroller

-
Image
Although the CRT has largely disappeared from our everyday lives, there was a decades-long timeframe when this was effectively the only display available. It’s an analog display for an analog world, and now that almost everything electronic is digital, these amazing pieces of technology are largely relegated to retro gaming and a few other niche uses. [Maurycy] has a unique CRT that’s small enough to fit in a handheld television, but since there aren’t analog TV stations anymore, he decided to build his own with nothing but an 8-bit microcontroller and a few other small parts . The microcontroller in question is a fairly standard 8-bit AVR. These microcontrollers have one major limitation when generating the VHF and UHF radio signals needed for analog TV: their natural clock speed is much too low. The maximum output frequency of a pin on this microcontroller is only 6 MHz, and [Maurycy] needs something about two orders of magnitude faster. To solve this problem, [Maurycy] uses a qui...
Post a Comment
Get this one»

Reviving a Cursed Sun SPARCstation IPX

-
Image
SPARCstation IPX running Solaris 2.6. (Credit: This Does Not Compute, YouTube) The best part about retro computing is the idea that you’ll save some poor system from being scrapped and revive it to a working state, at which point you can bask in the glory of a job well done. That’s when reality often strikes hard, and you find yourself troubleshooting a maddening list of issues as you question everything about your life choices. Such was the case with [This Does Not Compute] over at YouTube with a Sun SPARCstation IPX that decided to put up a big fight. This is the second video of a series. In the first installment, the PSU was repaired, and a boot failure was diagnosed. The system’s onboard diagnostic led to the assumption that one of the 8 kB SRAM ICs was defective.  You can readily get SRAM replacements, so it seemed to be an easy fix. Unfortunately, the fun was only beginning as the system reported the exact same error after the SRAM was replaced. After flipping a virtua...
Post a Comment
Get this one»

ESP32: When Is A P4 A P4, But Not The P4 You Thought It Was

-
Image
We’re used to electronic parts of the same type staying predictably the same, sometimes over many years. An early Z80 from the mid 1970s can be exchanged with one from the end of production a few years ago, for example. This week, we’ve had DMs from several readers who’ve found that this is not always the case, and the culprit is surprising. Espressif has released a new revision of their P4 application processor , and though it’s ostensibly the same, there are a couple of changes that have been catching people out. The changes lie in both hardware and software, in that there’s a pin that’s changed from NC to a power rail, a few extra passives are needed, and firmware must be compiled separately for either revision. The problem is that they are being sold as the same device and appear in some places under the same SKU! This is leading to uncertainty as to which P4 revision is in stock at wholesalers. We’ve been told about boards designed for the old revision being assembled with the n...
Post a Comment
Get this one»

Slug Algorithm for On-GPU Rendering of Fonts with BĂ©zier Curves now in Public Domain

-
Image
The Slug Algorithm has been around for a decade now, mostly quietly rendering fonts and later entire GUIs using BĂ©zier curves directly on the GPU for games and other types of software, but due to its proprietary nature it didn’t see much adoption outside of commercial settings. This has now changed with its author, [Eric Lengyel], releasing it to the public domain without any limitations. Originally [Eric] had received a software patent in 2019 for the algorithm that would have prevented anyone else from implementing it until the patent’s expiration in 2038. Since 2016 [Eric] and his business have however had in his eyes sufficient benefit from the patent, making it unnecessary to hold on to it any longer and retain such exclusivity. To help anyone with implementing their own version of the algorithm, there is a GitHub repository containing reference shader implementations with plenty of inline comments that should help anyone with some shader experience get started. Although pr...
Post a Comment
Get this one»

Conway’s Game of Life With Physical Buttons

-
Image
Conway’s Game of Life excels in its simplicity, creating a cellular automaton on a 2D grid where each cell obeys a set of very simple rules that determine whether a cell is ‘alive’ or ‘dead’. After setting an initial condition the ‘game’ then evolves naturally from there, creating an endless series of patterns as a simplified form of bacterial evolution. Of course, setting an initial state and then watching cells light up or fade away seems like a natural fit for light-up buttons. After struggling with intrusive thoughts related to such a project for a while, [Michal Zalewski] finally gave in, creating a pretty amazing looking result . Although there is no set size for the game board, [Michal] was constrained by his budget for the selected NKK JB15LPF-JF tactile buttons, resulting in a 17×17 matrix. That’s 289 buttons, for those keeping score, which comes down to over $1,000 over at e.g. Digikey even with quantity-based pricing. Add to this the custom PCB and a Microchip AVR128DA64 s...
Post a Comment
Get this one»

How Long Can a Quadcopter Drone Fly on Just Solar?

-
Image
The final second prototype flying. (Credit: Luke Maximo Bell, YouTube) The dream of fully powering everything from aircraft to cars on just the power generated from solar panels attached to the machine remains a tempting one, but always seems to require some serious engineering including putting the machine on a crash diet. The quadcopter that [Luke Maximo Bell] tried to fly off just solar power is a good case in point, as the first attempt crashed after three minutes and wrecked its solar panels. Now he’s back with a second attempt that ought to stay airborne for as long as the sun is shining. Among the flaws with the first prototype were poor support for the very thin and fragile PV panels, requiring much better support on the carbon fiber frame of the drone. To support the very large solar array, the first drone’s arms were made to be very long, but this interfered with maneuvering, so the second version got trimmed down and the array raised above the frame. This saved 70 gra...
Post a Comment
Get this one»