Mining Bitcoin On The ESP32 For Fun, Definitely Not Profit

March 19, 2019 by Lewin Day 7 Comments

Bitcoin’s great, if you sold at the end of 2017. If you’re still holding, your opinion might be a little more sour. The cost to compete in the great hashing race continues to rise while cryptocurrency values remain underwhelming. While getting involved at the top end is prohibitively expensive, you can still have some fun with the basic concepts – as [Jake] did, by calculating Bitcoin hashes on the ESP32.

It’s a project that is very much done for fun, rather than profit. [Jake] notes that even maxing out both cores, it would take 31 billion years to mine one block at current difficulty levels. Regardless, the underlying maths is nothing too crazy. Double-hashing the right data with the SHA256 algorithm is all that’s required, a task that is well within the ESP32’s capabilities. There’s hardware acceleration available, too – though this is weirdly slower than doing it in software.

Overall, you’re not going to get rich hashing Bitcoin on a cheap microcontroller platform. You might just learn something useful, though. If this isn’t weird enough though, you could always try the same thing on a 1970s Xerox Alto.

How To Interface Sega Controllers, And Make Them Wireless

March 18, 2019 by Lewin Day 9 Comments

The Sega Genesis, or Mega Drive as it was known outside North America, was a popular console for the simple fact that Sega did what Nintendidn’t. Anachronistic marketing jokes aside, it brought fast scrolling 16-bit games to a home console platform and won many fans over the years. You may find yourself wanting to interface with the old controller hardware, and in that case, [Jon Thysell] is here to help.

[Jon] has done the work required to understand the Sega controller interface, and has shared his work on Github. The interface is an interesting one, and varies depending on the exact console and controller hardware used. The original Master System, with its D-pad and two buttons, simply uses six pins for the six switches on the controller. The 3-button Genesis pad gets a little more advanced, before things get further complicated with the state-machine-esque 6-button pad setup.

[Jon] helpfully breaks down the various interfaces, and makes it possible to interface them with Arduinos relatively easily. Sharing such work allows others to stand on the shoulders of giants and build their own projects. This nets us work such as [Danilo]’s wireless Genesis controller build. By combining the knowledge of the Sega protocol with a few off-the-shelf Arduinos and Bluetooth parts, it makes whipping up a wireless controller easy.

In this day and age, most console controllers can be readily interfaced with a PC with a variety of simple solutions – usually USB. You might feel like trying something harder though, for instance interfacing modern Nintendo controllers to a C64. Video after the break.

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The MiniITX Retro System

March 16, 2019 by Brian Benchoff 12 Comments

There are hundreds of modern, retrocomputing projects out there that put ancient CPUs and chips in a modern context. The Neon816 from [Lenore] is perhaps one of the most impressive projects like this we’ve seen. It’s a classic system in a modern form factor, with modern video output, mashed together into a MiniITX motherboard.

The powerhouse of this computer is the Western Design Center W65C816 CPU. This is the second generation of the venerable 6502 CPU, the same chip found in everything from the Commodore 64 to the Apple II to the Nintendo Entertainment System. The 65816 is a 6502 at start-up until you flip a bit in a register, at which time the signalling on the address bus becomes much weirder. We’ve seen some single board computers based on the 65816 before and The 8-Bit Guy has a few ideas to build a computer around this CPU, but for the foreseeable future work on that will be trapped in development hell.

Of note, the Neon816 will feature DVI output (I guess technically you can just run the analog signals through the connector), a PS/2 Joystick input, two Atari / Sega joystick ports, MIDI in and out, a PC-style floppy disc connector, and a Commodore serial bus. It’s a hodge-podge of classic retrotainment, all in a single MiniITX motherboard.

The key other feature of the Neon816 is an FPGA, specifically a Lattice XP2 8000 LUT chip that is used for video and audio. This is combined with 1MB of main RAM (looks like a simple SRAM) and 128k of Flash storage for the ROM. There’s also an SD card in there for storage.

Right now, [Lenore] is populating the first prototype board, and we can’t wait to see some video generated with this impressive little system.

Home Brewing Rig Gets A Particle Upgrade

March 15, 2019 by Lewin Day No comments

Home brewing is a pastime that can be as much an art or a science as you make it, depending on your predilections. [Brandon Satrom] is one who leans very much towards the science side. There’s plenty that can be done to monitor and control a brew, and [Brandon] is one of many who have built custom hardware to help get the best possible results. Now, that hardware was due for an upgrade.

[Brandon]’s original BrewBuddy system relied on the Particle Photon, a useful platform that was nonetheless getting on in years. With the launch of the new Particle Argon, [Brandon] set his sights on new features that were possible with the added horsepower available. Graphics were added to the LCD screen, and a piezo sensor to detect the start of the fermentation process. This is in addition to the original temperature monitoring and plotting features of the first build.

The upgrade from one microcontroller platform to another can be fraught with headaches, but in this case, only minor changes were needed. 3 lines of code were changed to account for different pin assignments, and the rest fell neatly into place. It’s a testament to the compatibility of the Particle platforms that this upgrade was so easy.

We’ve talked about the 3rd generation Particle boards before, and we expect to see them turning up in many more builds to come. Video after the break.

[Thanks to dcschelt for the tip!]

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Emulating An Altair 8800 On An Apple II

March 13, 2019 by Lewin Day 5 Comments

The Altair 8800 was, to its creators, a surprise hit. Despite looking nothing like what we would today consider to be a computer, it sold thousands of units almost immediately upon its launch, way back in 1975. A few years later, the Apple II burst onto the scene, and the home computer revolution began in earnest.

Emulating older machines on newer hardware has always been a thing, and [option8] has coded an Altair 8800 emulator for the Apple II. Of course, if you don’t have one lying around, you can run this emulator on an Apple II emulator right in your browser. Honestly, it’s emulators all the way down.

As far as emulators go, this is a particularly charming one, with the Altair’s front panel displayed in glorious color on the Apple’s 40 column screen. Replete with a full set of switches and blinking LEDs, it’s a tidy low-resolution replica of the real thing. Instructions to drive it are available, along with those for another similar emulator known as Apple80.

If that still hasn’t quenched your thirst, check out this Game Boy emulator that lives inside emacs.

ATtiny Gets A Tiny Software UART

March 13, 2019 by Lewin Day 27 Comments

Modern microcontroller platforms spoil us with their performance and expansive spec sheets. These days it’s not uncommon to be developing for a cheap micro that has a clock rate well in excess of 100MHz, with all manner of peripherals baked in. DACs, WiFi, you name it – it’s in there, with a bunch of libraries to boot. It wasn’t always this way, and sometimes you would even find yourself lacking hardware serial support. In these cases, the bitbanged software UART is your friend, and [MarcelMG] decided to document just how it’s done.

The amateur programmer’s first recourse may be to use delays to properly time the output data stream. This has the drawback of wasting processor cycles and doesn’t let the microcontroller do much else useful. Instead, [Marcel] discusses the proper way to do things, through the use of interrupt service routines and hardware timers.

[Marcel]’s implementation is for the ATtiny24A, though it should be easily portable to other AVR8 processors. Taking up just 2 bytes of RAM and 276 bytes of program space, it’s compact – which is key on resource-limited 8-bit devices. The code is available on Github if you fancy trying it out yourself.

It’s a technique that is more than familiar to the old hands, but useful to those new to the art. It can be particularly useful if you need to get data out of a legacy platform with limited options. As times change, it’s important to pass on the techniques of yesteryear to the new generation. Of course, if things are really tight, you can even do a half-duplex UART on a single pin.

Old Meets New In 3D Printed Telegraph

March 12, 2019 by Tom Nardi 12 Comments

We often think of 3D printing as a way to create specific components in our builds, everything from some hard-to-find little sprocket to a custom enclosure. More and more of the projects that grace the pages of Hackaday utilize at least a few 3D printed parts, even if the overall build itself is not something we’d necessarily consider a “printed” project. It’s the natural progression of a technology which at one time was expensive and complex becoming increasingly available to the maker and hacker.

But occasionally we see 3D printing used not to create new devices, but recreate old ones. A perfect example is the almost entirely 3D printed telegraph system created by [Matt]. Projects like this help bring antiquated technology back to a modern audience, and can be an excellent educational tool. Showing someone a diagram of how the telegraph worked is one thing, but being able to run off a copy on your 3D printer and putting a working model in their hands is quite another.

[Matt] acknowledges that he’s hardly the first person to 3D print a telegraph key, but says that he’d never seen the complete system done before. The key is perhaps the component most people are familiar with from film and old images, but alone it’s really nothing more than a momentary switch. To actually put it to use, you need a telegraph sounder on the receiving end to “play” the messages.

The sounder is a somewhat more complex device than the key, and uses an electromagnet to pull down a lever and produce an audible clicking noise. In the most basic case, the coil is directly connected to the key, but in a modern twist [Matt] has added a MOSFET into the circuit so the electromagnet is triggered locally within the sounder. This prevents sparks from eroding the contacts in the key, and alleviates problems associated with current loss over long wire runs.

We’ve previously seen 3D printing used to revive vintage games which are no longer available such as “The Amazing Dr. Nim”, and how modern techniques such as additive manufacturing can help put World War II aircraft back in the air. While there was never much question that 3D printing would be a big part of our future, it would seem to be taking a fairly active role in preserving our past as well.