Arduboy FX Mod-Chip: Now You’re Playing With Power

March 4, 2021 by Tom Nardi 13 Comments

Traditionally, a forum full of technical users trying integrate their own hardware into a game system for the purposes of gaining unfettered access to its entire software library was the kind of thing that would keep engineers at Sony and Nintendo up at night. The development and proliferation of so called “mod chips” were an existential threat to companies that made their money selling video games, and as such, sniffing out these console hackers and keeping their findings from going public for as long as possible was a top priority.

But the Arduboy is no traditional game system. Its games are distributed for free, so a chip that allows users to cram hundreds of them onto the handheld at once isn’t some shady attempt to pull a fast one on the developers, it’s a substantial usability improvement over the stock hardware. So when Arduboy creator Kevin Bates found out about the grassroots effort to expand the system’s internal storage on the official forums, he didn’t try to put a stop to it. Instead, he asked how he could help make it a reality for as many Arduboy owners as possible.

Now, a little less than three years after forum member Mr.Blinky posted his initial concept for hanging an external SPI flash chip on the system’s test pads, the official Arduboy FX Mod-Chip has arrived. Whether you go the DIY route and build your own version or buy the ready-to-go module, one thing is for sure: it’s a must-have upgrade for the Arduboy that will completely change how you use the diminutive handheld.

Continue reading “Arduboy FX Mod-Chip: Now You’re Playing With Power” →

Bike Wheel Light Flashes Just Right

February 4, 2021 by Kristina Panos 22 Comments

When it comes to safely riding a bike around cars, the more lights, the better. Ideally, these lights would come on by themselves, so you don’t have to remember to turn them on and off every time. That’s exactly the idea behind [Jeremy Cook]’s latest build — it’s an automatic bike light that detects vibration and lights up some LEDs in response.

The build is pretty simple — a coin cell-powered ATtiny85 reads input from a spring vibration sensor and flashes the LEDs. This is meant to complement [Jeremy]’s primary bike light, which is manually operated and always on. We especially like that form follows function here — the board shape is designed to be zip-tied to the spokes so it’s as close to the action as possible. He cleverly used cardboard and a laser cutter to mock up a prototype for a board that fits between the spokes. Pretty cool for your second professionally-fabbed PCB ever, if you ask us. Ride past the break to check out the build video.

If you don’t think fireflies on your spokes are enough to keep you safe, go full rainbow party bike.

Continue reading “Bike Wheel Light Flashes Just Right” →

Your NES Classic Mini Controller, On Your Desktop Computer

January 24, 2021 by Jenny List 7 Comments

The NES Classic Mini was one of the earlier releases in what became a wider trend for tiny versions of classic retro consoles to be released. Everybody wanted one but numbers were limited, so only the lucky few gained this chance to relive their childhood through the medium of Donkey Kong or Mario Brothers on real Nintendo hardware. Evidently [Albert Gonzalez] was one of them, because he’s produced a USB adapter for the Mini controller to allow it to be used as a PC peripheral.

On the small protoboard is the Nintendo connector at one end, an ATtiny85 microcontroller, and a micro-USB connector at the other. The I2C interface from the controller is mapped to USB on the ATtiny through the magic of the V-USB library, appearing to the latter as a generic gamepad. It’s thought that the same interface is likely to also work with the later SNES Classic Mini controller. For the curious all the code and other resources can be found in a GitHub repository, so should you have been lucky enough to lay your hands on a NES Classic Mini then you too can join the PC fun.

The mini consoles were popular, but didn’t excite our community as much as could be expected. Our colleague Lewin Day tool a look at the phenomenon last summer.

Auto Tuning For A Vintage Stereo

December 13, 2020 by Jenny List 8 Comments

In 1984 there weren’t many ways to listen to high-quality music, so an FM tuner was an essential part of any home hi-fi system. The Pioneer TX-950 picked up by [The Curious Lorenz] would have been someone’s pride and joy, with its then-cutting-edge microprocessor control, digital PLL tuning, and seven-segment displays. Astoundingly it doesn’t have an auto-tuning function though, so some work to implement the feature using an ATtiny85 was called for.

A modern FM tuner would be quite likely to use an all-in-one tuner chip using SDR technology under the hood, but this device from another era appears to be a very conventional analog tuner to which the PLL and microprocessor have been grafted. There are simple “Up” and “Down” buttons and a “Station tuned” light. One might imagine that given these the original processor could have done autotune. At least the original designers were kind enough to provide the ATtiny with the interfaces it needs. Pressing either button causes it to keep strobing its line until the “Station tuned” line goes high, at which point it stops. It’s an extremely simple yet effective upgrade, and since the ATtiny is so small it’s easily placed on top of the original PCB. The result is an ultra-modern tuner from 1984, that’s just that little bit more modern than it used to be.

If you don’t have a vintage FM radio, you can always build its modern equivalent.

This 3D Printed “Bladeless” Fan Gets It Done Cheap

September 1, 2020 by Tom Nardi 33 Comments

Not long after Dyson unveiled their “bladeless” fan, a fairly steady stream of ever cheaper clones have been hitting the market. But this 3D printed version created by [Elite Worm] must surely be one of the most budget-friendly takes on the concept. If you’ve got a 3D printer, we’d wager you’ve already got most of the parts required to build your own.

To be clear, of course there’s a blade. They aren’t magic, obviously. The fan is just small, and hidden inside the base. Air is pulled from the sides and bottom, and into the ring mounted to the top of the unit. When the air eventually exits the thin slit in the ring, it “sticks” to the sides due to the Coandă effect and produces a low pressure zone in the center. That’s all a fancy way of saying that the air flow you get from one of these gadgets is several times greater than what the little dinky fan would be capable of under normal circumstances. That’s the theory, anyway.

We can’t promise that all the physics are working as they should in this 3D printed version, but in the video after the break it certainly appears to be moving a considerable amount of air. It’s also quite loud, but that’s to be expected given it’s using a brushless hobby motor. To get it spinning, [Elite Worm] is using a Digispark ATtiny85 connected to a standard RC electronic speed control (ESC). The MCU reads a potentiometer mounted to the side of the fan and converts that to a PWM signal required by the ESC.

Beyond the electronics, essentially every piece of this project has been printed on a standard desktop 3D printer. An impressive accomplishment, though we probably would have gone with a commercially available propeller for safety’s sake. On the other hand, the base of the fan should nicely contain the shrapnel created should it explode at several thousand RPM. Probably.

Continue reading “This 3D Printed “Bladeless” Fan Gets It Done Cheap” →

Retro Game Bow Tie

August 4, 2020 by Orlando Hoilett 4 Comments

[Greg] loves hacking his bow ties. Back in high school, he added some bright RGB LEDs to the bow tie he wore to prom and even won the male best-dressed award. Recently he decided to try another bow tie hack, this time giving his tie some retro arcade game feels.

He decided to use an ATtiny85 and to experiment doing some more lower-level programming to refresh his skills. He wrote all his libraries from scratch which really helped him learn a lot about the ATtiny in the process. This also helped him make sure his code was as efficient as possible since he had quite a bit of memory constraints using the ATtiny85 (only 512 bytes of RAM).

He designed the body of the bow tie with wood. He fit all the electronics inside the body while allowing the ATtiny to protrude out of the body giving his bow tie some wanted hacker aesthetic. Of course, he needed to access the toggle switch to play the game, so he made a slot for that as well.

Nice addition to the electronics bow tie collection on Hackaday. Really aesthetic design if you ask us. And you know how much we love retro games.

Continue reading “Retro Game Bow Tie” →

Spoofing An Analog Rotary Knob With An ATtiny, And Vampiric Power

July 14, 2020 by Donald Papp 22 Comments

[Mitxela]’s repair of a Roland JV-1080 (a rack-mounted 90s-era synthesizer) sounds simple: replace a broken rotary encoder on the front panel. It turned out to be anything but simple, since the part in question is not today’s idea of a standard rotary encoder at all. The JV-1080 uses some kind of rotary pulse switch, which has three outputs (one for each direction, and one for pushing the knob in like a button.) Turn the knob in one direction, and one of the output wires is briefly shorted to ground with every detent. Turn it the other way, and the same happens on the other output wire. This is the part that needed a replacement.

The finished unit uses a modern rotary encoder and microcontroller in place of the original part, and implements a few tricks to power it.

Rather than track down a source for the broken part, [Mitxela] opted to replace it with a modern rotary encoder combined with an ATtiny85 microcontroller to make it act like something the JV-1080 understands and expects. There was an additional wrinkle, however. The original rotary pulse switch is an entirely passive device, and lives at the end of a four-conductor cable with no power provided on it. How could the ATtiny85 be powered without resorting to running a wire to a DC voltage supply somewhere? Success was had, but it did take some finessing.

For the power, it turns out that the signal wires are weakly pulled up to +5 V and [Mitxela] used that for a power supply to the microcontroller. Still, by itself that wasn’t enough, because the ATtiny85 can easily consume more current than the weak pullups can source. We really recommend reading all the details in [Mitxela]’s writeup, but the short version is that the ATtiny85 does two things.

First, it minimizes its power usage by spending most of its time in sleep mode (consuming barely any power at all) and uses an interrupt to wake up just long enough to handle knob activity. Second, the trickle of power from the weak pullups doesn’t feed the ATtiny directly. It charges a 100 uF capacitor through a diode, and that is what keeps the microcontroller from browning out during its brief spurts of activity. Even better, after browsing the datasheet for the ATtiny, [Mitxela] saw it was possible to use the built-in ESD protection diodes for this purpose instead of adding a separate component.

It’s a neat trick and makes for a very compact package. Visit the project’s GitHub repository to dive into the nitty gritty. In the end, a single assembly at the end of a 4-wire connector acts just like the original passive component, no extra wires or hardware modifications needed.

When opening older hardware it’s never quite certain what will be found on the inside. But at least [Mitxela]’s repair duties on this synth didn’t end up with him tripping out on LSD.