CircuitPython Macro Pad Is One Build That Won’t Bite

May 13, 2020 by Kristina Panos No comments

Have you built a macro keypad yet? This is one of those projects where the need can materialize after the build is complete, because these things are made of wishes and upsides. A totally customized, fun build that streamlines processes for both work and play? Yes please. The only downside is that you actually have to like, know how to build them.

Suffer no more, because [Andy Warburton] can show you exactly how to put a macro pad together without worrying about wiring up a key switch matrix correctly. [Andy]’s keypad uses the very affordable Seeeduino Xiao, a tiny board that natively runs Arduino code. Since it has a SAMD21 processor, [Andy] chose to run CircuitPython on it instead. And lucky for you, he wrote a separate guide for that.

Practicalities aside, the next best thing about macro keyboards is that they can take nearly any shape or form. Print a case from Thingiverse as [Andy] did, or build it into anything you have lying around that’s sturdy enough to stand up to key presses and won’t slide around on your desk.

No room left on the desk? Build a macro foot stool and put those feet to work.

Via r/circuitpython

The ABCs Of Adding QMK To A WASD Keyboard

May 5, 2020 by Kristina Panos 21 Comments

[Oleg] is a software engineer who appreciates a good keyboard, especially since coming over to the dark side of mechanical keebs. It’s true what they say — once you go clack, you never go back.

Anyway, before going full nerd with an ortholinear split ergo keyboard, [Oleg] had a nice little WASD with many upsides. Because the ErgoDox is oh so customizable, his use of the WASD had fallen by the wayside.

That’s because the ErgoDox can run QMK firmware, which allows the user to customize every key they see and add layers of functionality. Many people have converted all kinds of old keebs over to QMK by swapping out the native controller for a Teensy, and [Oleg] was sure it would work for the WASD.

[Oleg] got under the hood and found that the controller sits on a little removable board around the arrow keys and talks to the main PCB through two sets of double-row header pins. After some careful probing with a ‘scope, the controller board revealed its secrets and [Oleg] was able to set up a testing scheme to reverse engineer the keyboard matrix by connecting each row to an LED, and all the columns to ground. With next to no room for the Teensy, [Oleg] ended up strapping it to the back of the switch PCB and wiring it quite beautifully to the header pins.

With Teensy and QMK, it’s easy to make a keyboard any way you want, even if you’re all thumbs.

Break Time Is Calling On The Rainbow Connection

May 4, 2020 by Kristina Panos 6 Comments

Like some of us, [Mister M] is prone to staying glued to his seat too long in this new era of working from home. And you know what they say about a body at desk — it tends to stay at desk until it absolutely must rise up to find food or use the restroom.

Thanks to this nifty new break time reminder, [Mister M] has a third call to answer that demands he get up. Every hour, the NeoPixel ring in this old dial-deficient phone fills up completely and switches over to an attention-getting rainbow animation. If [Mister M] stays seated, playtime is over. All the lights start flashing red, and the phone starts beeping incessantly until he walks across the room and either pushes the momentary button or lifts the handset to reset the timer.

We love that [Mister M] incorporated all of the phone’s original inputs and outputs into this project, because it’s such a cool old dog and bone. No need to drop a dime, just whistle at the break button to check out the build video.

This grille-faced phone was probably part of an intercom system. Incidentally, you can make an intercom system with two standard-style phones of this vintage.

Continue reading “Break Time Is Calling On The Rainbow Connection” →

DIY Ribbon Controller For A DIY Synth

May 3, 2020 by Kristina Panos 13 Comments

There’s kind of a special joy in making instruments, no matter how simple or complex they are. Even if it’s a straight-up noisemaker, that’s noise you can be proud of. And besides, noise plus rhythm equals music.

Whenever you’re ready to have some next-level fun, try making controllers for your DIY instruments. Synthesizers of all stripes are often controlled with various types of potentiometers. While it would definitely be an interesting exercise to make your own standard twist-style potentiometer, [lonesoulsurfer] shows that making a ribbon controller is relatively easy.

A ribbon controller is essentially a deconstructed potentiometer that uses your finger to actuate the wiper. Here the wiper is made from Velostat, a fun, low-cost conductive material that’s also pressure-sensitive. The rest of the ribbon controller is a sandwich of thin copper plates and non-conductive plastic mounted on a wood base.

But what’s a fun controller without a fun instrument to control? As a special bonus, [lonesoulsurfer] made a little square wave-squirting synth based on the 4046 hex inverter and included the schematic for it. Slide your finger past the break to check ’em both out.

Depending on what you have lying around, it may be easier to make analog instruments like this rubber band boinger or its country cousin, the wheelbarrow bass.

Continue reading “DIY Ribbon Controller For A DIY Synth” →

Mass Mask-Making Masterclass

May 2, 2020 by Kristina Panos 7 Comments

Just as 3D printers around the world have been churning out face shields, the thread injectors of home sewists have been stitching up fabric masks. Over the past several weeks, [Becky Stern] has made them for friends, family, neighbors, and anyone in her community who happens upon the box of free masks she’s left at a nearby bus stop. This is in addition the scores she has made and donated to health care workers so they can extend the life of their N95 masks.

If you’re going to make more than a few of anything, it just makes sense to make multiples at the same time and adjust the process for batch production. [Becky Stern] has some great ideas for ramping up assembly even further that include cutting out multiple main mask pieces at the same time, and ironing the pleats of several masks round robin style so you don’t waste time while they cool.

Even if you don’t dabble in the fabric arts, her method of kitting out the process of mask making is an interesting look into small-scale production.

Our favorite idea concerns the side bindings and the straps, which are the last part of the build and take the longest to do. [Becky] makes several miles of straps ahead of time with a 3D printed bias tape folder and then sews them all into a continuous strip. She can add the short side bindings to a bunch of masks at once, feeding them in one after the other so they end up strung together like sausages. Then she can just snip them apart and keep going, having saved both time and thread. Watch [Becky] make a single mask after the break and see how easy it is.

If sewing is a no-go for you, there are plenty of ways to help the PPE effort by firing up that printer.

Continue reading “Mass Mask-Making Masterclass” →

How To Keep Unique Equipment Running When Parts Run Out

April 23, 2020 by Donald Papp 16 Comments

[JGlass] deals with public-facing technology, which he says includes things like theatre equipment, retail displays, and museum displays. Many of these pieces of technology are literally one-of-a-kind devices, even if they were constructed from what was once off-the-shelf, commercially available parts. When these machines need servicing, replacement parts aren’t always available, and reverse engineering comes in handy. He recently began documenting exactly how to approach this process by using the identification and replacement of an obsolete 7-segment industrial display as an example.

The particular part shown is the Lascar EM32-4-LED, which up and died in a unique piece of equipment. The trouble is that the EM32-4-LED is out of production and unobtainable, and the Programmable Logic Controller (PLC) that drives the whole thing is a black box that cannot be modified. It’s very good news that a datasheet exists, but that’s often just a starting point. To create a one-off, drop-in solution requires a combination of research, troubleshooting, and design work.

To do this, [JGlass] starts off by walking through datasheet elements and explains that it’s important to build a high level understanding of function first, then drill down into details, and always be ready to verify, challenge, or throw out one’s assumptions. After establishing a high level understanding comes matching physical evidence to things like block and functional diagrams, then cracking open the faulty component to see if anything else can be learned. Only then are multimeters and probes taken out for more active research. All of this sleuthing must always be done with the end goal firmly in mind: creating a new device that acts like the one being replaced. Without focus, one can easily get lost in details and unknowns.

Reverse Engineering is a process, and the more tools, the better. If you missed our earlier post about a hacker’s guide to JTAG, here’s your chance to check it out and be all the more prepared for the next time you need to do some electron detective work of your own.

DIY Magsafe Charger Feeds Off 12 V Solar Battery

April 19, 2020 by Donald Papp 18 Comments

[Steve Chamberlin] has a spiffy solar-charged 12 V battery that he was eager to use to power his laptop, but ran into a glitch. His MacBook Pro uses Apple’s MagSafe 2 connector for power, but plugging the AC adapter into the battery via a 110 VAC inverter seemed awfully inefficient. It would be much better to plug it into the battery directly, but that also was a problem. While Apple has a number of DC power adapters intended for automotive use, none exist for the MagSafe 2 connector [Steve]’s mid-2014 MacBook Pro uses. His solution was to roll his own MagSafe charger with 12 VDC input.

Since MagSafe connectors are proprietary, his first duty was to salvage one from a broken wall charger. After cleaning up the wires and repairing any frayed bits, it was time to choose a DC-DC converter to go between the MagSafe connector and the battery. The battery is nominally 12 volts, so the input of the DC-DC converter was easy to choose, but the output was a bit uncertain. Figuring out what the MagSafe connector expects took a little educated guesswork.

The original AC adapter attached to the charger claimed an output of 20 volts, another Apple adapter claimed a 14.85 V output, and a third-party adapter said 16.5 volts. [Steve] figured that the MagSafe connectors seemed fine with anything in the 15 to 20 V range, so it would be acceptable to use a 12 V to 19 V DC-DC boost converter which he had available. The result worked just fine, and [Steve] took measurements to verify that it is in fact much more efficient than had he took the easy way out with the inverter.

MagSafe has been displaced by USB-C nowadays, but there are plenty of MagSafe devices still kicking around. In a pinch, keep in mind that a little bit of filing or grinding is all that’s needed to turn MagSafe 1 into MagSafe 2.