Concentric Rings Keep This Calendar Perpetually Up To Date

July 26, 2020 by Dan Maloney 7 Comments

The variety of ways that people find to show the passage of time never ceases to amaze us. Just when you think you’ve seen them all, someone comes up with something new and unusual, like the concentric rings of this automated perpetual calendar.

What we really like about the design that [tomatoskins] came up with is both its simplicity and its mystery. By hiding the mechanism, which is just a 3D-printed internal ring gear attached to the back of each ring, it invites people in to check it out closely and discover more. Doing so reveals that each ring is hanging from a pinion gear on a small stepper motor, which rotates it to the right point once a day or once a month. Most of the clock is made from wood, with the rings themselves made using the same technique that woodturners use to create blanks for turning bowls — or a Death Star. We love the look the method yields, although it could be even cooler with contrasting colors and grains for each segment. And there’s nothing stopping someone from reproducing this with laser-cut parts, or adding rings to display the time too.

Another nice tip in this write up is the trick [tomatoskins] used to label the rings, by transferring laser-printed characters from paper to wood using nothing but water-based polyurethane wood finish. That’s one to file away for another day.

Son Of Rothult

July 26, 2020 by Brian McEvoy 6 Comments

We are continuously inspired by our readers which is why we share what we love, and that inspiration flows both ways. [jetpilot305] connected a Rothult unit to the Arduino IDE in response to Ripping up a Rothult. Consider us flattered. There are several factors at play here. One, the Arduino banner covers a lot of programmable hardware, and it is a powerful tool in a hardware hacker’s belt. Two, someone saw a tool they wanted to control and made it happen. Three, it’s a piece of (minimal) security hardware, but who knows where that can scale. The secure is made accessible.

The Github upload instructions are illustrated, and you know we appreciate documentation. There are a couple of tables for the controller pins and header for your convenience. You will be compiling your sketch in Arduino’s IDE, but uploading through ST-Link across some wires you will have to solder. We are in advanced territory now, but keep this inspiration train going and drop us a tip to share something you make with this miniature deadbolt.

Locks and security are our bread and butter, so enjoy some physical key appreciation and digital lock love.

Skee-Ball Scoring With Coin Slot Switches

July 20, 2020 by Kristina Panos 4 Comments

Bowling is great and all, but the unpredictability of that little ball jump in Skee-Ball is so much more exciting. You can play it straight, or spend a bunch of time perfecting the 100-point shot. And unlike bowling, there’s nothing to reset, because gravity gives you the balls back.

In one of [gcall1979]’s earlier Skee-Ball machines, gravity assisted the scoring mechanism, too: each ball rolls back to the player and lands in a lane labeled with the corresponding score, which is an interesting engineering challenge in its own right. He decided to build automatic scoring into his newest Skee-Ball machine.

At the bottom of each cylinder is an arcade machine coin door switch with a long wire actuator. These had to be mounted so they’re close enough to the hole, but out of the way of the balls.

Each switch is wired up to an Arduino Mega along with four large 7-segments for the score, and a giant 7-segment to show the number of balls played. Whenever the game is reset, a servo drops a door to release the balls, just like a commercial machine.

The arcade switches work pretty well, especially once he bent the wire into hook shape to cover more area. But they do fail once in a while, maybe because the targets are full-size, but the balls are half regulation size. For the next one, [gcall1979] is planning to use IR break-beam targets which ought to work with any size ball. If you prefer bowling, you won’t strike out with break-beam targets there, either.

Bluepill Copies Code So You Don’t Have To

July 17, 2020 by Al Williams 5 Comments

You really should learn to read Morse code. But if you can’t — or even if you can, and just want a break — you can always get a computer to do it. For example, [jmharvey1] has a decoder that runs on a cheap Bluepill dev board.

The device uses a touchscreen and a few common components. The whole thing cost about $16. You can see it at work along with a description of the project in the video below.

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Four On The Floor For Your Virtual Race Car

July 17, 2020 by Al Williams 2 Comments

There was a time when building realistic simulations of vehicles was the stuff of NASA and big corporations. Today, many people have sophisticated virtual cockpits or race cars that they use with high-resolution screens or even virtual reality gear. If you think about it, a virtual car isn’t that hard to pull off. All you really need is a steering wheel, a few pedals, and a gear shifter. Sure, you can build fans to simulate the wind and put haptics in your seat, but really the input devices alone get you most of the way there. [Oli] decided he wanted a quick and easy USB gear shifter so he took a trip to the hardware store, picked up an arcade joystick, and tied it all together with an Arduino Leonardo. The finished product that you can see in the video below cost about $30 and took less than six hours to build.

The Leonardo, of course, has the ability to act like a USB human interface device (HID) so it can emulate a mouse or a keyboard or a joystick. That comes in handy for this project, as you would expect. The computer simply has to read the four joystick buttons and then decide which gear matches which buttons. For example up and to the left is first gear, while 4th gear is only the down button depressed. A custom-cut wooden shifter plate gives you the typical H pattern you expect from a stick shift.

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Arduino Plays NES Games

July 15, 2020 by Bryan Cockfield 14 Comments

Watching the advancement of technology is interesting enough by looking at improved specifications for various components as the years go by. But clock speeds, memory size, and power consumption are all fairly intangible compared to actual implementation of modern technology when compared to days of yore. For example, this $40 microcontroller can do what a video game console was able to do in the 80s for a tenth of the (inflation adjusted) price.

The NESDUE is an emulator for NES games which runs completely on an Arduino Due. The Arduino does have some limitations that have to be worked around to get the Nintendo to work, though. For one, it needs to be overclocked to be playable and it also needs a workaround to get past the memory limit of 96 kB of RAM. From there, a small screen is wired up along with a controller (from a Super Nintendo) and the gaming can begin.

This is an impressive feat for an Arduino platform to accomplish, especially with the amount of memory tweaking that has to happen. This might be the most advanced gaming system available that runs everything on an Arduino, right up there with the Arduinocade which can provide an arcade-like experience straight from the Arduino as well.

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Surgery On The Arduino IDE Makes Bigger Serial Buffers

July 13, 2020 by Al Williams 20 Comments

It is pretty well-known that I’m not a big fan of the Arduino infrastructure. Granted, these days you have more options with the pro IDE and Platform IO, for example. But the original IDE always gives me heartburn. I realized just how much heartburn the other day when I wanted to something very simple: increase the receive buffer on an ATmega32 serial port. The solution I arrived at might help you do some other things, so even if you don’t need that exact feature, you still might find it useful to see what I did.

Following this experience I am genuinely torn. On the one hand, I despise the lackluster editor for hiding too much detail from me and providing little in the way of useful tools. On the other hand, I was impressed with how extensible it was if you can dig out the details of how it works internally.

First, you might wonder why I use the IDE. The short answer is I don’t. But when you produce things for other people to use, you almost can’t ignore it. No matter how you craft your personal environment, the minute your code hits the Internet, someone will try to use it in the IDE. A while back I’d written about the $4 Z80 computer by [Just4Fun]. I rarely have time to build things I write about, but I really wanted to try this little computer. The parts sat partially assembled for a while and then a PCB came out for it. I got the PCB and — you guessed it — it sat some more, partially assembled. But I finally found time to finish it and had CP/M booted up.

The only problem was there were not many good options for transferring data back and forth to the PC. It looked like the best bet was to do Intel hex files and transfer them copy and paste across the terminal. I wanted better, and that sent me down a Saturday morning rabbit hole. What I ended up with is a way to make your own menus in the Arduino IDE to set compiler options based on the target hardware for the project. It’s a trick worth knowing as it will come in handy beyond this single problem.

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