Arduboy On The Big Screen

We’re big fans of the Arduboy here at Hackaday, but we’ll admit its tiny screen isn’t exactly ideal for long gaming sessions. There are some DIY builds of the open source handheld that use a larger SPI OLED display, though you’re relatively limited on what kind of changes can be made to the hardware before the games start balking. But as [Nick Bild] shows with his Arduboy home console, hacking the core system library opens up a lot of interesting possibilities.

Games written for the Arduboy make use of a common library that handles all the low-level hardware stuff, which includes a display() function to push the graphical data out to an SPI-connected OLED display. What [Nick] has done is re-write that function to instead output to a custom VGA generator running on the TinyFPGA BX. He had to delete support for the Arduboy’s RGB LEDs because he needed the extra pins, but that shouldn’t cause much of a problem in terms of software support.

This does mean that games need to be recompiled against the modified library to work on his hardware, but as the vast majority of Arduboy software is open source anyway, that’s not much of a problem. We particularly like the Super Game Boy style border  you get around the display at no extra cost.

At this point the hardware looks less like a console and more like a breadboard filled with jumpers, so we’re interested in seeing this project taken to its logical conclusion. A custom PCB, enclosure, and possibly even support for using the original NES controllers would turn this into proper system worthy of any hacker’s game room. You could even put the games on custom cartridges if you wanted, though a flash chip that holds the system’s entire library would be quite a bit more convenient.

FIR Filters For Xilinx

Digital filters are always an interesting topic, and they are especially attractive with FPGAs. [Pabolo] has been working with them in a series of blog posts. The latest covers an 8th order FIR filter in Verilog.  He covers some math, which you can find in many places, but he also shows how an implementation maps to DSP slices in a device. Then to reduce the number of slices, he illustrates folding which trades delay time for slice usage.

Folding takes a multi-stage parallel multiplication and breaks it into fewer multiplications done over a longer period of time. This reuses slices to reduce the number required for high-order filters.

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Arduino And FPGA Done Differently

FPGA guru [Max Maxfield] recently took a look at the XLR8 (pronounced accelerate) board from a company called Alorium. On the surface, it looks like another Arduino UNO clone. But instead of a CPU, it contains an Intel MAX10 FPGA that runs a softcore AVR processor. Of course, that’s only part of the story. If the board was just a mock Arduino using an FPGA, that’s not very interesting for practical purposes. However, by incorporating accelerator blocks or XBs, you can add FPGA modules to the soft CPU. [Max] shows an example that you can see in the video below where an FPGA block controls servos more easily than a standard Arduino. There’s also a version that looks like an Arduino Nano, but can clock much faster as well as use the XBs.

In addition to prebuilt XBs, there is a workflow to build your own if you are familiar with working with FPGAs. The products aren’t exactly new, but we enjoyed [Max’s] take on the product. We also appreciated the simple code examples showing exactly how you would convert a program to use the accelerated functions. Continue reading “Arduino And FPGA Done Differently”

Surf’s Up, A Styrofoam Ball Rides The Waves To Create A Volumetric Display

We are big fans of POV displays, particularly ones that move into 3D. To do so, they need to move even faster than their 2D cousins. [danfoisy] built a volumetric display that doesn’t move LEDs or any other digital display through space, or project light onto a moving surface. All that moves here is a bead of styrofoam and does so at up to 1 meter per second. Having low mass certainly helps when trying to hit the brakes, but we’re getting ahead of ourselves.

danfoisy vdatp 3d simulation

[danfoisy] and son built an acoustic levitator kit from [PhysicsGirl] which inspired the youngster’s science fair project on sound. See the video by [PhysicsGirl] for an explanation of levitation in a standing wave. [danfoisy] happened upon a paper in the Journal Nature about a volumetric display that expanded this one-dimensional standing wave into three dimensions. The paper described using a phased array of ultrasonic transducers, each with a 40 kHz waveform.

After reading the paper and determining how to recreate the experiment, [danfoisy] built a 2D simulation and then another in 3D to validate the approach. We are impressed with the level of physics and programming on display, and that the same code carried through to the build.

[danfoisy] didn’t stop with the simulations, designing and building control boards for each 100 x 100 10 x 10 grid of transducers. Each grid is driven by 2 Intel Cyclone FPGAs and all are fed 3D shapes by a Raspberry Pi Zero W. The volume of the display is 100 mm x 100 mm x 145mm and the positioning of the foam ball is accurate down to .01 mm though currently there is considerable distortion in the positioning.

Check out the video after the break to see the process of simulating, designing, and testing the display. There are a number of tips along the way, including how to test for the polarity of the transducers and the use of a Python script to place the grids of transducers and drivers in KiCad.

danfoisy vdatp schematic  danfoisy vdatp board layout

Continue reading “Surf’s Up, A Styrofoam Ball Rides The Waves To Create A Volumetric Display”

Reverse Engineering The Weather Channel’s Magic

For American readers of a certain age, Local on the 8s likely holds a special spot in your heart. The program, once a staple of The Weather Channel, would provide viewers with a text and eventually graphical depiction of their local forecast set to some of the greatest smooth jazz ever heard outside of an elevator. In the days before smartphones, or even regular Internet access for that matter, these broadcasts were a critical part of planning your day in the 1980s through to the early 2000s.

Up until recently the technical details behind these iconic weather reports were largely unknown, but thanks to the Herculean efforts of [techknight], the fascinating engineering that went into the WeatherSTAR 4000 machines that pumped out current conditions and Shakin’ The Shack from CATV distribution centers all over the US for decades is now being documented and preserved. The process of reversing the hardware and software has actually been going on for the last couple of years, but all those juicy details are now finally going to be available on the project’s Hackaday.IO page.

It all started around Christmas of 2018, when an eBay alert [techknight] had configured for the WeatherSTAR 4000 finally fired off. His offer was accepted, and soon he had the physical manifestation of Local on the 8s in his own hands. He’d reasoned that getting the Motorola MC68010 machine working would be like poking around in a retrocomputer, but it didn’t take long for him to realize he’d gotten himself into a much larger project than he could ever have imagined.

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Framed PONG Is Picture Perfect

How cool would it have been if arcade cabinets had acrylic panels all along that let you gaze upon the field of TTL chips within? When [Jürgen Müller] scored the innards of an original 1972 PONG machine, that’s exactly what the plan was: build a suitable cabinet that re-imagines PONG as a sleek and stunning work of art.

Instead of trying to cram a CRT in that nice mahogany cabinet, [Jürgen] opted to use an 8″ TFT screen. But get this: [Jürgen] built a Spartan 6 FPGA-based upscaler to adds the scan lines, blur, and afterglow that make it look like the classic PONG experience.

[Jürgen] also built an interface board that amplifies the sound, splits the video out into sync and brightness for the upscaler, and provides 5 V to the PONG circuit board. [Jürgen] decided to circumvent the board’s native voltage regulator in the name of keeping things cool.

[Jürgen] says the project’s web page is in a preliminary stage right now with more information to come. We sure hope that includes a video of it in action. For now, you can check out the files for the interface PCB, the FPGA board, and a list of the fonts.

Should you ever get tired of classic PONG, try playing it in one dimension.

Thanks for the tip, [Anonymous].

Make Room For A New Arduino Competitor – With Native Brainf*ck!

With so many smaller and more capable microcontroller boards on the market it’s now fairly safe to say that the classic Arduino footprint and form factor is rather outdated. That’s not to say that there’s no fight left in the old contender though, and to prove it here’s a new platform in the familiar style set by the venerable Atmel-based board. [Eduardo Corpeño]’s Brainfuino is an Arduino competitor that runs everyone’s favourite esoteric programming language, Brainf*ck. (Keeping it SFW, folks.)

And in case you mistake it for a Brainf*ck emulator on a PCB then stand ready to be corrected, for this board runs the language natively in a Brainf*ck softcore on a Lattice MachXO2 FPGA. This is the real deal, on which only a true genius or masochist would dare to code.

The board itself is very neatly executed with a graphical style that presents more than a nod to the original Arduino. On this board is the FPGA, 256 kB ROM and 138 kB RAM, an STM32 to provide a USB serial port and an analogue input, and a level shifter to provide Arduino-style 5 V logic on the pins. We can see it’ll provide hours of fun to anyone interested in learning Brainf*ck, but besides that it has potential as an Arduino-shaped FPGA board. We like the joke, we like the graphical and engineering design, but underneath that lies quite the technical achievement.

Brainf*ck has made it to Hackaday before, not least in this jaw-dropping relay computer.