Watch Linux Boot On Your Hackaday Superconference Badge

February 29, 2020 by Jenny List 4 Comments

Last year’s Hackaday Superconference badge was an electronic tour de force, packing an ECP5 FPGA shoehorned into a Game Boy-like form factor and shipping with a RISC-V core installed that together gave an almost infinite badge hacking potential. It did not however run Linux, and that’s something [Greg Davill] has addressed, as he’s not only running Linux on his badge, but also a framebuffer that allows him to use the badge screen as the Linux terminal screen. Finally you can watch Linux boot on your Superconference badge itself, rather than over its serial port.

He’s achieved this by changing essentially everything: from the new VexRiscv CPU core, to new video drivers and a VGA terminal courtesy of Frank Buss, now part of the LiteVideo project. It’s not quite a fully fledged Linux powerhouse yet, but you can find it in a GitHub repository should you have a mind to try it yourself. Paging back through his Twitter feed reveals the effort he’s put into this work over the last few months, and shows that it’s been no easy task.

For those keeping score at home, this is an open hardware design, running an open CPU core, with community-designed open-source peripherals, compiled by an open-source toolchain, running an open-source operating system. And it’s simply a fantastic demo for the badge, showing off how flexible the entire system is. One of the best parts of writing for Hackaday is that our community is capable of a huge breadth of amazing pieces of work, and this is an exemplar of that energy. We can’t wait to see what Greg and any other readers tempted to try it will come up with.

If you’d like to refresh your memory over the 2019 Supercon badge, here’s our write-up at the time.

Machine Inside Of A Chip: How Sprite_TM Built The FPGA Game Boy Badge

February 19, 2020 by Mike Szczys 12 Comments

Kids of the 1990’s would call you a liar if you told them that within thirty years you’d go to a conference and be handed a Super Nintendo Entertainment System to wear around your neck. But that’s what happened with the badge Jeroen Domburg, aka [Sprite_TM], designed for the 2019 Hackaday Superconference. It’s built in the Game Boy form factor, complete with a cartridge slot, beautiful screen, and the familiar button layout. But there’s so much more here, like the HDMI port on the bottom and the ability to completely reconfigure the device by dropping a binary file onto it over USB.

Of course what makes this possible is the FPGA at the heart of the design. The story of how the badge was developed is shared in great detail during Sprite’s Supercon talk. The timeline, the hardware choices, and the oopses along the way make for a great story. But what you really don’t want to miss is how he built the machine inside of the FPGA — the collection of Verilog code known as “gateware” that brings together the System-on-a-Chip (SoC). From his delight at being able to spawn more processor cores by changing a single variable, to the fascinating SNES-inspired graphics subsystem, the inside story shared below is even more interesting than the physical device itself.

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Supercon Keynote: Megan Wachs Breaks Down RISC-V

January 27, 2020 by Elliot Williams 17 Comments

The 2019 Hackaday Superconference kicked off with a marvelous, and marvelously geeky, keynote talk on the subject of RISC-V by Dr. Megan Wachs. She is VP of Engineering at SiFive, a company that makes RISC-V processors in silicon, but the talk is a much more general introduction to the RISC-V open instruction-set architecture (ISA) and why you’d care. The short answer to the latter is the same reason you care about any other open standard: it promotes interoperability, reusable toolchains, and will result in us all having access to better and faster CPUs.

The video is embedded below, and it’s absolutely worth a watch. Unfortunately, The video is missing the first few minutes, you can follow along through her slides (PDF) and read through our brief recap below of what fell down the video hole.

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New Part Day: LED Driver Is FPGA Dev Board In Disguise

January 24, 2020 by Elliot Williams 51 Comments

Our new part of the day is the ColorLight 5A-75B, a board that’s meant to drive eight of those ubiquitous high-density color LED panels over gigabit Ethernet. If you were building a commercial LED wall, you’d screw a bunch of the LED panels together, daisy-chain a bunch of these boards to drive them, supply power, and you’d be done. Because of that high-volume application, these boards are inexpensive, around $15 each, and available as quickly as you can get stuff shipped from China.

But we’re not here to talk commercial applications. Managing fast Ethernet and pushing so many pixels in real time is a task best handled by an FPGA, and [Tom Verbeure] noticed that these things were essentially amazing FPGA development boards and started hacking on them. [q3k] put it up on GitHub, and you can follow along with the chubby75 reverse engineering project to dig into their secrets.

While the first generations of these boards used the old-standby Spartan 6, things got interesting for fans of open FPGA tools when newer versions were found using the Lattice ECP5-25 chips, the little brother of the stonking big chip [Sprite_TM] used on the 2019 Hackaday Supercon badge. If you want to grab one you’re looking for ColorLight boards marked with revision 6 or 7 as of this writing.

What does this mean? For the price of a gourmet hamburger, you get an FPGA that’s big enough to run a RISC-V softcore, two 166 MHz, 2 MB SDRAMS, flash for the FPGA bitstream, a bazillion digital outputs on 5 V level shifters, and two gigabit Ethernet ports. The JTAG port is broken out in 0.1″ headers, and it works with OpenOCD, which is ridiculously convenient. How’s that for a well-stocked budget FPGA dev board that’s served by a completely open toolchain? Continue reading “New Part Day: LED Driver Is FPGA Dev Board In Disguise” →

Hackaday Podcast 051: Pointing With Your Tongue, C64 Touchpad, USB Killcord, And Audacity Does Everything

January 24, 2020 by Mike Szczys 2 Comments

Hackaday editors Mike Szczys and Elliot Williams sort through the hacks you might have missed over the past seven days. In FPGA hacking news, there’s a ton of work being done on a newly discovered FPGA dev board. Kristina has a new column on input devices, kicking it off with tongue-actuated controllers. We wax philosophical about what data you need to backup and what you should let go. Plus Audacity is helping tune up CNC machines, copper tape is the prototyper’s friend, and fans of Open should take note of this laptop project.

Take a look at the links below if you want to follow along, and as always tell us what you think about this episode in the comments!

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)

Continue reading “Hackaday Podcast 051: Pointing With Your Tongue, C64 Touchpad, USB Killcord, And Audacity Does Everything” →

COSMAC ELF Lives Again, In FPGA

January 23, 2020 by Bryan Cockfield 44 Comments

Looking around at the personal computing markets in modern times, there seem to be a lot of choices in the market. In reality, though, almost everything runs on hardware from a very small group of companies, and software is often available across platforms. This wasn’t the case in the personal computing boom of the 70s and 80s, where different computers were wildly different in hardware and even architecture. The Cosmac ELF was one of the more interesting specimens from this era, and this one has been meticulously reproduced on an FPGA.

The original hardware was based on an RCA 1802 microprocessor and had a rudimentary (by today’s standards) set of switches and buttons as the computer’s inputs. It was low cost, even for the time, but was one of the first single-board computers available. This recreation is coded in SpinalHDL and the simplicity of the original hardware makes it relatively easy to understand. The FPGA is cycle-accurate to the original hardware, too, which makes it nearly perfect even without any of the original hardware.

The project’s creator, [Winston] aka [wel97459], found that SpinalHDL made this project fun to work on (and released his code on his GitHub page), and was able to get the code down to just 1500 lines to recreate the original hardware. It’s very impressive, and also an accessible read for anyone interested in some of the more unique computers offered during the early computer renaissance in the 70s.

Using Lookup Tables To Make The Impossible Possible

January 10, 2020 by Dan Maloney 60 Comments

Embarrassing confession time: I never learned my multiplication tables in grade school. Sure, I had the easy tables like the twos and the fives down, but if asked what 4 x 7 or 8 x 6 was, I’d draw a blank. As you can imagine, that made me a less than stellar math student, and I was especially handicapped on time-limited tests with lots of long multiplication problems. The standard algorithm is much faster when you’ve committed those tables to memory, as I discovered to my great woe.

I was reminded of this painful memory as I watched Charles Lohr’s 2019 Supercon talk on the usefulness and flexibility of lookup tables, or LUTs, and their ability to ease or even completely avoid computationally intensive operations. Of course most LUT implementations address problems somewhat more complex than multiplication tables, but they don’t have to. As Charles points out, even the tables of sines and logarithms that used to populate page after page in reference books have been ported to silicon, where looking up the correct answer based on user input is far easier than deriving the answer computationally.

Yes, this is a Minecraft server all thanks to LUTs.

One of the most interesting examples of how LUTs can achieve the seemingly impossible lies in an old project where Charles attempted to build a Minecraft server on an ATMega168. Sending chunks (the data representations of a portion of the game world) to clients is the essential job of a Minecraft server, and on normal machines that involves using data compression. Rather than trying to implement zlib on an 8-bit microcontroller, he turned to a LUT that just feeds the raw bytes to the client, without the server having the slightest idea what any of it means. A similar technique is used by some power inverters, which synthesize sine wave output by feeding one full cycle of values to a DAC from a byte array. It’s brute force, but it works.

Another fascinating and unexpected realization is that LUTs don’t necessarily have to be software. Some can be implemented in completely mechanical systems. Charles used the example of cams on a shaft; in a car’s engine, these represent the code needed to open and close valves at the right time for each cylinder. More complicated examples are the cams and gears once found in fire control computers for naval guns, or the programming cards used for Jacquard looms. He even tips his hat to the Wintergatan marble machine, with its large programming drum and pegs acting as a hardware LUT.

I found Charles’ talk wide-ranging and fascinating. Originally I thought it would be an FPGA-heavy talk, but he didn’t actually get to the FPGA-specific stuff until the very end. That worked out fine, though — just hearing about all the cool problems a LUT can solve was worth the price of admission.

And for the curious, yes, I did eventually end up memorizing the multiplication tables. Oddly, it only clicked for me after I started playing with numbers and seeing their relationships using my first calculator, which ironically enough probably used LUTs to calculate results.

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