Overengineering The Humble USB Power Bank

Back in the flip phone days, you could get through the whole weekend before you had to even think about plugging the thing in. But as the processing power of our mobile devices increased, so to did their energy consumption. Today you’re lucky if your phone doesn’t die before you make it home at the end of the day. To avoid the horrors of having to live without their mobile devices, many people have resorted to lugging around small “power banks” to keep their phones topped off.

That said, the “Ultimate 18650 Power Bank” created by [Kennedy Liu] is on a whole new level. Only true Road Warriors need apply for this particular piece of kit. Inside the 3D printed enclosure is…well, pretty much everything. It’s got an internal inverter to power your AC devices, a Qi wireless charging coil, an adjustable DC output, displays for all relevant voltages, and naturally plenty of USB ports to charge your gadgets. Oh, and some RGB LEDs tossed in for good measure.

[Kennedy] packed a lot of hardware into this relatively small package, and in the video after the break, shows off exactly how everything is arranged inside of this power bank. A big part of getting the whole thing together is the 3D printed frame, which includes carefully designed insets for all of the key components. So if you want to build your own version, you’ll need to get the exact same hardware he used to make sure the puzzle fits together. Luckily, he’s provided links for all the relevant components for exactly that purpose.

Now, you might be wondering about the wisdom of packing all this electronic gear into a thermoplastic enclosure. But [Kennedy] has thought about that; in addition to tacking a heatsink onto pretty much everything, he’s added fans for active cooling and a fairly robust thermal overload protection scheme. By mounting thermally controlled switches to the heatsinks of the high-output components, the system can cut power to anything getting too hot before it has a chance to melt the plastic (or worse).

Most of the DIY power banks we’ve seen in the past have been little more than a simple collection of 18650 cells, so it’s interesting to see one with so much additional functionality packed in. Admittedly some elements of the construction are, to quote the great Dave Jones, “a bit how ya doin.” But with some refinements we think it would be a very handy device to have in your arsenal.

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A Customizable Open Source Mechanical Numpad

Mechanical keyboards with reduced key counts are all the rage these days, but while those streamlined input devices might look cool on your desk, there are times when the traditional number pad or navigation keys are quite handy. Rather than just going without, [Mattia Dal Ben] decided to put together his own mechanical auxiliary input device for when the main board just isn’t cutting it.

[Mattia] is calling his creation the YamPAD, which stands for Yet Another Mechanical numPAD. One of the major goals for the project is to produce a design that’s easy for others to replicate and customize. His PCB has a socket designed to fit an Arduino Pro Micro, which combined with the QMK firmware, offers a wide array of configuration options. All that’s left is to add in the Cherry MX switches and some 1N4148 diodes.

But if you want to take things a little further, [Mattia] has that covered as well. The PCB design has provisions for RGB LED back-lighting should you find yourself in need of crunching some numbers in the dark. There’s even a spot for a 0.91″ OLED display if you really want to take things to the next level.

As of right now, the YamPAD is just a bare PCB, but [Mattia] is planning to design a 3D printed enclosure for it soon. The sketches he’s done so far depict a printed case which we think bears more than a passing resemblance to a Wii Fit Balance Board, but of course being a fully open source project, you’ll be free to design your own case based on the PCB’s dimensions. It would be interesting to see what other kind of customization the community might come up with once the design is finalized.

If you like the idea of the YamPAD, you might also want to check out the kbord we covered back in 2017. If you want to see the full keyboard done in this DIY open hardware style, there are already some choice entries into the field.

Giving An Industrial Push Button USB, Elegantly

[Glen]’s project sounds perfectly straightforward: have a big industrial-style push button act as a one-key USB keyboard. He could have hacked something together in any number of ways, but instead he decided to create a truly elegant solution. His custom PCB mates to the factory parts perfectly, and the USB cable between the button and the computer even fits through the button enclosure’s lead hole.

It turns out that industrial push buttons have standardized components which can be assembled in an almost LEGO-like manner, with components mixed and matched to provide different switch actions, light indicators, and things of that nature. [Glen] decided to leverage this feature to make his custom PCB (the same design used in his one-key keyboard project) fit just like a factory component. With a 3D printed adapter, the PCB locks in just like any other component, and even lines up with the lead hole in the button’s enclosure for easy connecting of the USB cable.

What does [Glen] use the big button for? Currently he has two applications: one provides a simple, one-button screen lock on a Linux box running a virtual machine at his place of work. It first disengages the keyboard capture of the virtual machine, then engages the screen lock on the host. The other inserts a poop emoji into Microsoft documents. Code and PCB design files for [Glen]’s small keyboards are available on GitHub.

A Classy USB Knob For The Discerning Computerist

The keyboard and mouse are great, we’re big fans. But for some tasks, such as seeking around in audio and video files, a rotary encoder is a more intuitive way to get the job done. [VincentMakes] liked the idea of having a knob he could turn to adjust his system volume or move forward and backwards through a stream in VLC, but he also wanted to be able to repeatedly enter keyboard commands with it; something commercial offerings apparently weren’t able to do.

So he decided to build his own USB knob that not only looks fantastic, but offers the features he couldn’t find anywhere else. It’s another project which proves that DIY projects don’t have to look DIY. In fact, they can often give their commercial counterparts a run for their money. But this “Infinity USB Knob” isn’t just a pretty face, it allows the user to do some very interesting things such as quickly undo and redo changes to see how they compare.

As you might imagine, the electronics for this project aren’t terribly complex. The main components are the Adafruit Trinket M0 microcontroller and the EC11 rotary encoder itself. To provide nice visual feedback he added in a NeoPixel ring, but that’s not strictly necessary if you’re trying to rig this up yourself. Though we have to say the lighting effects are a big part of what makes this build look so good.

Though certainly not the only part. The aluminum enclosure, combined with the home theater style knob on the encoder, really give the finished product a professional look. We especially like his method of drilling out the top of the case and filling in the holes with epoxy to create easy and durable LED diffusers. Something to keep in mind for your next control panel build, perhaps.

[VincentMakes] has done an excellent job of documenting the hardware and software sides of this build on Hackaday.io, and gives the reader enough information that replicating this project should be pretty straightforward for anyone who’s interested. While we’ve seen several rotary encoder peripherals for the computer in the past, we have to admit this is one of the most compelling yet from a visual and usability standpoint. If this build doesn’t make you consider adding a USB knob to your arsenal, nothing will.

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Sim Panel Proves You Can Always Use More Buttons

Many people enjoy playing flight simulators or making the occasional orbit in Kerbal Space Program, but most are stuck controlling the onscreen action with nothing more exotic than a keyboard and mouse. A nice compromise for those that don’t have the space (or NASA-sized budget) to build a full simulator cockpit is a USB “button box” that you can plug in whenever you need a couple dozen extra knobs, switches, and lights.

If you’ve been considering building one for yourself, this incredible build by [nexprime] should prove quite inspirational. Now at this point, a box of buttons hooked up to a microcontroller isn’t exactly newsworthy. But there are a few features that [nexprime] packed in which we think make this particular build worth taking a closer look at.

For one, the powder coated 8.5” x 10” enclosure is absolutely gorgeous. The console itself was purchased from a company called Hammond Manufacturing, but of course it still took some work to turn it into the object you’re currently drooling over. A CNC machine was used to accurately cut out all the necessary openings, and the labels were laser etched into the powder coat.

But not all the labels. One of the things we like best about this build is that [nexprime] thought ahead and didn’t just design it for one game. Many of the labels are printed on strips of paper which slide into translucent plastic channels built into the front of the box. Not only does this allow you to change out the overlays for different games, but the paper labels look fantastic when lit with the LED strips placed behind the channels.

Internally, [nexprime] used a SparkFun Pro Micro paired with a SX1509 I/O expander. The electronics are all housed on professionally manufactured PCBs, which gives the final build an incredibly neat look despite packing in 68 separate inputs for your gaming pleasure. On the software side this box appears as a normal USB game controller, albeit one with a crazy number of buttons.

If this build doesn’t have enough switches and buttons for you, don’t worry. This Kerbal Space Program cockpit has banks of switches below and above the player, so one can more realistically scramble for the correct onet to flip when things start going sideways. On the other hand, we’ve seen slightly less intense builds if you’re not quite ready to take out a loan just to get into orbit.

Immersive Augmented Reality On A Budget

By now we’ve all seen the cheap headsets that essentially stick a smartphone a few inches away from your face to function as a low-cost alternative to devices like Oculus Rift. Available for as little as a few dollars, it’s hard to beat these gadgets for experimenting with VR on a budget. But what about if you’re more interested in working with augmented reality, where rendered images are superimposed onto your real-world view rather than replacing it?

As it turns out, there are now cheap headsets to do that with your phone as well. [kvtoet] picked one of these gadgets up for $30 USD on AliExpress, and used it as a base for a more capable augmented reality experience than the headset alone is capable of. The project is in the early stages, but so far the combination of this simple headset and some hardware liberated from inexpensive Chinese smartphones looks to hold considerable promise for delivering a sub-$100 USD development platform for anyone looking to jump into this fascinating field.

On their own, these cheap augmented reality headsets simply show a reflection of your smartphone’s screen on the inside of the lenses. With specially designed applications, this effect can be used to give the wearer the impression that objects shown on the phone’s screen are actually in their field of vision. It’s a neat effect to be sure, but it doesn’t hold much in the way of practical applications. To turn this into a useful system, the phone needs to be able to see what the wearer is seeing.

To that end, [kvtoet] relocated a VKWorld S8 smartphone’s camera module onto the front of the headset. Beyond its relatively cost, this model of phone was selected because it featured a long camera ribbon cable. With the camera on the outside of the headset, an Android application was created which periodically flashes a bright LED and looks for reflections in the camera’s feed. These reflections are then used to locate objects and markers in the real world.

In the video after the break, [kvtoet] demonstrates how this technique is put to use. The phone is able to track a retroreflector laying on the couch quickly and accurately enough that it can be used to adjust the rendering of a virtual object in real time. As the headset is moved around, it gives the impression that the wearer is actually viewing a real object from different angles and distances. With such a simplistic system the effect isn’t perfect, but it’s exciting to think of the possibilities now that this sort of technology is falling into the tinkerer’s budget.

If you don’t want to go the DIY route, Leap Motion has been teasing an open source augmented reality headset which has us quite excited. We’re still waiting on the hardware, but that hasn’t stopped hackers from coming up with some fascinating AR applications in the meantime.

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Restoring A Forgotten Dot-Matrix Printer

Dot matrix printers are the dinosaurs that won’t go extinct. They are not unlike a typewriter with the type bars behind the ink ribbon replaced by a row of metal pins controlled by solenoids, each pin being capable of printing a single pixel. At their best they could deliver a surprising level of quality, but their sound once heard is not forgotten, because it was extremely LOUD.

[Wpqrek] bought an old dot-matrix printer, a Commodore MPS 803. Sadly it didn’t live up to the dot-matrix reputation for reliability in that it didn’t work, some of its pins weren’t moving, so he set to on its repair. Behind each of those pins was a solenoid, and after finding a crack in the flexible ribbon to the head he discovered that some of the solenoids were open-circuit. On dismantling the head it became apparent that the wires had detached themselves from the solenoids, so he very carefully reattached new wires and reassembled the unit. Of course, he had no replacement for the flexible ribbon, so he made a replacement with a bundle of long lengths of flexible hook-up wire. This hangs out of the top of the printer as it follows the carriage, but for now it keeps the device working.

Dot-matrix printers are a favourite for our readership. Among others, we’ve seen another Commodore get the Python treatment, as well as an Apple capable of printing in full colour.