DC to DC conversion has come a long way. What was once took an electromechanical vibrator and transformer has been reduced to a PC board the size of a largish postage stamp that can be had for a couple of bucks on eBay. So why roll your own buck-boost converter for the ground up? Maybe because sometimes the best way to learn is by doing.
Continue reading “A Buck-Boost Converter From The Ground Up”
In the early 1980s when the 8-bit microcomputer boom was well under way, [Alan Faulds] was a student, and an owner of a Sinclair ZX81. He had ambitions to use it, in his words, “to control the world“, but since the Sinclair lacked an I/O port he was thwarted. He bought an expander board and a couple of I/O card PCBs from the British electronic supplier Maplin in the days when they were a mail order parts stockist rather than a chain of stores chasing Radio Shack’s vacated retail position.
Sadly for [Alan], he didn’t have the cash to buy all the parts to populate the boards, then the pressures of a final year at university intervened, and he never built those Maplin kits. They sat forgotten in their padded envelope for over three decades until a chance conversation with a friend reminded him of his unfinished student project. He sought it out, and set about recreating the board.
The ZX81 had a single port: a PCB edge connector at its rear that exposed all the Z80 processor’s lines. It was notorious for unreliability, as the tiniest vibration when a peripheral was connected would crash the machine. Maplin’s expansion system featured a backplane with a series of edge connector sockets, and cards with bare PCB edge connectors. Back in the 1980s it was easy to find edge connectors of the right size with the appropriate key installed, but not these days. [Alan] had to make one himself for his build.
The I/O card with its 8255 and brace of 74 series chips was a double-sided affair with vias made through the use of little snap-off hand-soldered pins. [Alan] put his ICs in sockets, a sensible choice given that when he powered it up he found he’d put a couple of the 74 chips in the wrong positions. With that error rectified the board worked exactly as it should, giving the little ZX three I/O ports, albeit with one of them a buffered output.
We haven’t featured the little Sinclair micro as often as we should have here at Hackaday, it seems to have been overshadowed by its ZX Spectrum successor. We did show you a VGA ZX81 emulated on an mbed though, and a rather neat color video hack for its Brazilian cousin.
The Internet of Things is a horrific waste of time, even though no one knows exactly what it is. What would make it better? Classic Commodore gear, of course. Now you can run your smart home with a Commodore 64 and Commodore Home, the newest smart home framework from [retro.moe].
Commodore Home comes with the standard smart home features you would expect. The home lighting solution is a dot matrix printer, a few gears, and string tied to the light switch. Activate the printer, and the lights turn on and off. Brilliant. Multiple light switches can be controlled by daisy chaining printers.
Security is important in the smart home, and while the intruder alarm isn’t completely functional, future versions of Commodore Home will dial a modem, log into a BBS, and leave a message whenever an authorized person enters your home.
All of this is possible thanks to advances in UniJoystiCle technology, also from [retro.moe]. This device takes a standard ESP8266 WiFi module and turns it into a smartphone-to-joystick port bridge for the Commodore 64.
Unlike every other piece of IoT hardware being sold today, Commodore Home won’t stop working when the company behind it goes belly up; Commodore has been dead for twenty years already. You can grab all the software for Commodore Home over on the Githubs, or you can check out the video below.
Continue reading “Commodore Home – Your Smart Home For 1983”
During the development of the greatest member of the Apple II family, the Apple IIgs, someone suggested to [Woz] that a sort of universal serial bus was needed for keyboards, mice, trackballs, and other desktop peripherals. [Woz] disappeared for a time and came back with something wonderful: a protocol that could be daisy-chained from keyboard to a graphics tablet to a mouse. This protocol was easily implemented on a cheap microcontroller, provided 500mA to the entire bus, and was used for everything from license dongles to modems.
The Apple Desktop Bus, or ADB, was a decade ahead of its time, and was a mainstay of the Mac platform until Apple had the courage to kill it off with the iMac. At that time, an industry popped up overnight for ADB to USB converters. Even today, there’s a few mechanical keyboard aficionados installing Teensies in their favorite input devices to give them a USB port.
While plugging an old Apple keyboard into a modern computer is a noble pursuit — this post was written on an Apple M0116 keyboard with salmon Alps switches — sometimes you want to go the other way. Wouldn’t it be cool to use a modern USB mouse and keyboard with an old Mac? That’s what [anthon] thought, so he developed the ADB Busboy.
Continue reading “Bringing USB Devices To The Apple Desktop Bus”
If you are interested in how a computer works at the hardware grass-roots level, past all the hardware and software abstractions intended to make them easier to use, you can sometimes find yourself frustrated in your investigations. Desktop and laptop computers are black boxes both physically and figuratively, and microcontrollers have retreated into their packages behind all the built-in peripherals that make them into systems-on-chips.
Continue reading “The BASIC Issue With Retro Computers”
As microcontrollers become more and more common, we see more ways to get a lot of performance out of one chip. A great example of this was the ESP8266 which was originally seen as a cheap WiFi card but has since blossomed into its own dev platform thanks to the horsepower hidden within. To that end, [Martin] is trying to push the now-ubiquitous WiFi chip even further by rolling out his own LCD driver for it from scratch.
The display of choice is the KeDei LCD 3.5″ module which was originally intended for use with a Raspberry Pi. [Martin] points out that this display isn’t optimized for speed, but after everything is said and done he has its clock line running at 40 MHz. To get this kind of speeds from the LCD, he depopulates the first shift register and adds his own fast-propagation circuit to establish a more-traditional serial addressing mode. With use of a WLCD driver that [Martin] also wrote, it is now relatively easy to draw on the screen very quickly with an ESP module. Check it out in the video below.
If you’re looking for your own tiny, cheap, fast display, this is one cool way to do it but we would suggest spinning a carrier board for both the ESP and the added circuitry. We’re looking forward to future projects which puts devices like these inside of really tiny magic mirrors, or uses them in other places where a small graphical display would be handy.
Continue reading “Slow 3.5″ Raspberry Pi LCD Hacked To 40 MHz With ESP8266”
If generations of Hollywood heist films have taught us anything, it’s that knocking off a bank vault is pretty easy. It usually starts with a guy and a stethoscope, but that never works, so the bad guys break out the cutting torch and burn their way in. But knowing how to harness that raw power means you’ve got to learn the basics of oxy-acetylene, and [This Old Tony]’s new video will get your life of crime off on the right foot.
In another well-produced video, [Tony] goes into quite a bit of detail on the mysteries of oxygen and acetylene and how to handle them without blowing yourself up. He starts with a tour of the equipment, including an interesting look at the internals of an acetylene tank — turns out the gas is stored dissolved in acetone in a porous matrix inside the tank. Working up the hoses, he covers the all-important flashback arrestors, the different styles of torches, and even the stoichiometry of hydrocarbon combustion and how adjusting the oxygen flow results in different flame types for different jobs. He shows how oxy-acetylene welding can be the poor man’s TIG, and finally satisfies that destructive urge by slicing through a piece of 3/8″ steel in under six seconds.
We’ve always wanted a decent oxy-acetylene rig, and [Tony] has convinced us that this is yet another must-have for the shop. There’s just so much you can do with them, not least of which is unsticking corroded fasteners. But if a blue wrench is out of your price range and you still want to stick metal together, you’ll want to learn how to braze aluminum with a propane torch.
