Automatic Coin Sorter Brings Order To Your Coin Jar

May 24, 2023 by 20 Comments

Few things hold as much promise as the old coin jar. Unfortunately, what’s generally promised is tedium, as one faces the prospect of manually sorting, counting, and rolling the accumulated change of cash transactions past. Unless, of course, you’ve got a fancy automatic coin sorter like this one.

True, many banks have automatic coin sorters, but you generally have to be a paying customer to use one. And there’s always Coinstar and similar kiosks, but they always find a way to extract a fee, one way or another. [Fraens] decided not to fall for either of those traps and roll his own machine, largely from 3D-printed parts. The basic mechanism is similar to that used in commercial coin counters, with an angled bowl rotating over an array of holes sized to fit various coins. Holes in the bottom of the feed bowl accept coins fed from a hopper and transport them up to the coin holes. The smallest coins fall out of the bowl first, followed by the bigger coins; each coin drops into a separate bin after passing through an optical sensor to count the number of each on an Arduino. Subtotals and a grand total of the haul are displayed on a small LCD screen. The video below shows the build and the sorter in operation.

[Fraens] built this sorter specifically for Euro coins, but it should be easy enough to modify the sorting slots for different currencies. It’s not the first coin sorter we’ve seen, of course, and while we applaud its design simplicity and efficient operation, it can’t hold a candle to the style of this decidedly less practical approach.

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Battery Bot Makes Sure Cordless Tool Packs Are Always Topped Up

May 24, 2023 by 19 Comments

There was a time not that long ago when every tool was cordless. But now, cordless power tools have proliferated to the point where the mere thought of using a plain old wrist-twisting screwdriver is enough to trigger a bout of sympathetic repetitive injury. And the only thing worse than that is to discover that the batteries for your tools are all dead.

As [Lance] from the “Sparks and Code” channel freely admits, the fact that his impressive collection of batteries is always dead is entirely his fault, and that’s what inspired his automatic battery charging robot. The design is pretty clever; depleted batteries go into a hopper, under which is a 3D-printed sled. Batteries drop down into the sled, which runs the battery out from under the hopper to the charging station, which is just the guts of an old manual charger attached to a lead screw to adjust the height of the charging terminals for different size batteries. When the battery is charged, the sled pushes it a little further into an outfeed hopper before going back to get another battery from the infeed side.

Of course, that all vastly understates the amount of work [Lance] had to put into this. He suffered through a lot of “integration hell” problems, like getting the charger properly connected to the Arduino running the automation. But with a lot of tweaking, he can now just dump in a bunch of depleted packs and let the battery bot handle everything. The video after the break shows all the gory details.

Of course, there’s another completely different and much simpler solution to the dead battery problem.

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Own More Than One ‘Scope? You’ve Got Nothing On This Guy!

May 24, 2023 by 18 Comments

We’re guessing that quite a few of our readers have a surprising amount of redundant test gear, and we ourselves have to admit that more than one instrument adorns our benches. But we are mere dilettantes, amateurs if you will, compared to [Volke Kloke]. He’s got 350 of them in his average American home, and we have to say, among them are some beauties.

The linked newspaper article is sometimes frustratingly light on the details, but fortunately he has a website all of his own where we can all get immersed in the details. Of particular interest is an instrument which doesn’t even have a CRT, the General Radio 338 string oscillograph used a mirror drum to catch a standing wave in a tungsten wire, but there are plenty more. Is your first ‘scope among them?

As we now live in the age of cheap digital ‘scopes, at any surplus sale you’ll see plenty of CRT-based instruments going for relative pennies. Of those, the more recent and high-end ones are still extremely useful instruments, and it’s not just misty-eyed reminiscing to say that they remain a worthy addition to any bench.

Want to know about early ‘scope tech? We’ve taken a look before.

Linux Fu: Making Progress

May 24, 2023 by 12 Comments

The computer world looks different from behind a TeleType or other hardcopy terminal. Things that tend to annoy people about Unix or Linux these days were perfectly great when you were printing everything the computer said to you. Consider the brevity of most basic commands. When you copy a file, for example, it doesn’t really tell you much other than it returns you to the prompt when it is done. If you are on a modern computer working with normal-sized files locally, not a big deal. But if you are over a slow network or with huge files, it would be nice to have a progress bar. Sure, you could write your own version of copy, but wouldn’t it be nice to have some more generic options?

One Way

The pv program can do some of the things you want. It monitors data through a pipe or, at least through its standard output. Think of it as cat with a meter. Suppose you want to write a diskimage to /dev/sdz:

cat diskz.img >/dev/sdz

But you could also do:

pv diskz.img >/dev/sdz

By default, pv will show a progress bar, an elapsed time, an estimated end time, a rate, and a total number of bytes. You can turn any of that off or add things using command line options. You can also specify things like the size of the terminal if it should count lines instead of bytes, and, in the case where the program doesn’t know what it is reading, the expected size of the transfer.

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New Zealand’s First Microcomputer May Be This 1802

May 24, 2023 by 13 Comments

Hardware hackers of a certain age likely got started with microcontrollers via the RCA 1802 — a relatively easy-to-use processor that was the subject of several excellent articles in Popular Electronics magazine back in the late 1970s. [Al’s Geek Lab] has an interview with [Hugh Anderson], who saw the articles and eventually designed the HUG1802, which may be the first microcontroller kit designed and sold in New Zealand.

The 1802 was very attractive at the time since it was inexpensive, static, didn’t require exotic voltages, and had a DMA system that allowed you to load software without complex ROMs. He initially marketed a kit unsuccessfully until an Australian company convinced him to create a proper PC board — the resulting kit was sold to about 100 customers.

The HUG1802 reminded us somewhat of the Quest Super Elf since it had a keypad, a cassette interface, and even a TV output. The 1802 had a DMA-enabled chip that made crude memory-mapped video output. The computer eventually morphed into the ETI 660, which they talk about at the end of the interview.

A lot of people built 1802 computers back in those days. If you don’t have an 1802, but you have an Arduino… ell, there’s always emulation.

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The Art And Science Of Making Beautiful Transparent Ice

May 24, 2023 by 43 Comments

For most of us, ice isn’t something we’ve thought about in detail since our high school science classes. For most of us, we pour some tap water into the ice trays, slam it in the freezer, and forget about it. Then we lob the frozen misshapen cubes into a beer and enjoy a quite literally ice-cold beverage.

However, there’s so much more fun to be had with ice if you really get into it. If you’ve ever wondered how pretentious cocktail bars make their fancy ice spheres or transparent cubes, read on!

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Hall Sensors Offer Drop-In Replacement For Drifting Game Console Joysticks

May 24, 2023 by 44 Comments

No bananas were harmed in the making of this Hall effect drift-proof joystick replacement. OK, not really — two bananas were turned to mush. But it’s OK, they’re just bananas, after all.

Why bananas, you ask? Because [Marius Heier] uses them to demonstrate what we all intuitively know — that rubbing something over and over again tends to wear it away — but engineers seem to have forgotten. Wear such as this, with resistance material rather than fruits, is what causes the dreaded drift, a problem that the world collectively spends $20 billion a year dealing with, according to [Marius].

While numbers like that seem to be firmly in class-action lawsuit territory, sometimes it’s best to take matters into your own hands and not wait for the courts. The fix [Marius] shows here is to yank the potentiometers off a PS4 joystick and replace them with contactless Hall effect sensors. The end of the shaft for each axis gets a diametral neodymium magnet attached to it, while a 3D printed bracket holds a tiny custom PCB in close proximity. The PCB has an AS5600 Hall sensor, which translates the shaft angle to an analog voltage output. After programming the chip over its I2C bus, the sensor outputs a voltage proportional to the angle of each shaft, just like the original pots, but without all the wear and tear.

While [Marius] is selling these as drop-in replacements for PS4 controllers, he plans to release all the design files so you can build one yourself. He also has his sights set on replacements for PS5 and Xbox controllers, so watch for those. This isn’t his first foray into joystick hacking, having shared his 3D Hall effect and haptic feedback joysticks with us previously.

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