Better Simulators With Homemade Potentiometers

May 24, 2019 by Bryan Cockfield 22 Comments

Perhaps you’ve played a flight simulator before, using something like a mouse and keyboard. That’s a fine experience, but like any other activity you can get a lot more out of it if you put a little more effort into the experience. Some will upgrade to a joystick for a modest improvement, and others will build incredible accurate cockpit replicas down to the smallest detail. The builders of these “pits” are always looking for ways of improving their setups, and it’s from this world that we find a method of building specialized, inexpensive hall-effect sensors.

A hall-effect sensor is a circuit that outputs a voltage based on the presence of an external magnetic field. These can be used to make compasses, but with a permanent magnet in close proximity can also be used to create a potentiometer-like device at lower cost and with higher precision than a similarly-priced pot. There was a method of building these in the simulator world using the housing of a Bic pen and some strong glue, but [LocNar] has improved on this method as well. He repurposed some bearings and some stock metal tubing in order to fabricate a professional-level sensor at a fraction of the cost.

This build is essentially a solution for anyone needing a potentiometer that’s easier to build, less expensive, has higher precision, and interacts with a digital input in a much more predictable (and programmable) way. Certainly this has applications in the simulator world, but will work for many other applications. If you’ve never thought about the intricacies (and shortcomings) of potentiometers, some other folks have taken a deep dive into that as well.

Thanks to [Keith O] for the tip!

Robot Arms Nudge The Hands Of Time In The Strangest Clock

May 9, 2019 by Dan Maloney 8 Comments

We see a lot of clocks here at Hackaday. Digital clocks, retro clocks, lots of Nixie clocks, binary clocks, and clocks that appear to be designed specifically to be unreadable. But this dual-servo kinematic clock is something we haven’t seen yet, and it’s certainly worth a mention.

[mircemk]’s idea is simple and hearkens back to grammar school days when [Teacher] put a large cardboard clock dial on the blackboard and went through the “big hand, little hand” drill. In this case, the static cardboard clock has been replaced by a 3D-printed dial and hands, while a pair of servos linked together by two arms takes the place of the teacher. The video below shows it in action; the joint in the linkage between the two servos has a screw sticking out that can be maneuvered across the clock face to reposition the hands. It’s a little jittery, though; [mircemk] might want to tune the servo loops up a bit or tighten the linkage joints to make things a little smoother.

Even with the shakes, we find it wonderfully weird and hard to stop watching. It reminds us a bit of this luminous plotting clock from a while back – same linkage, different display.

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Make The Surface Dial Do More Things, Such As MIDI

September 4, 2018 by Lewin Day 6 Comments

The Surface Dial is a $100+ rotary control. You can turn it, and it’ll make some basic stuff happen on your Microsoft Surface. It’s silver and sleek and elegant but fundamentally, it just works via emulated keyboard shortcuts. This doesn’t really do much for translating analog rotational motion into digital feedback in a nice way, so [SaveTheHuman5] created Elephant to fix this issue.

As standard, there are two ways to work with the Surface Dial as an end-user. The easiest way is to use existing utilities to map dial actions to shortcut keys. However, for interfacing with knobs and sliders in user interfaces, this is clunky. Instead, [SaveTheHuman5] drilled down and created their own utility using the Surface Dial API provided by Microsoft. This allows raw data to be captured from the dial and processed into whatever interactions your heart desires – as long as you’ve got the coding muscles to do it!

The Elephant software allows the knob to be used in two distinct modes – mouse capture, and MIDI. Mouse capture allows one to use a regular mouse to select UI objects, such as knobs in a music application, and then turn the Surface Dial to adjust the control. Anyone that’s struggled with tiny emulated rotary controls on a VST synth before would instantly know the value of this. In MIDI mode, however, the knob simply presents itself as a MIDI device outputting commands directly which would be more useful in performance environments in particular.

Overall, it’s a tidy hack of an otherwise quite limited piece of hardware – the only thing we’d like to see is more detail on how it was done. If you’ve got a good idea on how this could work, throw it down in the comments. And, if your thirst for rotary controls is still not satiated, check out this media controller. Video after the break.

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“Attempt” At Wristwatch Is A Solid Success

March 27, 2018 by Brian McEvoy 19 Comments

Sometimes silence is the best compliment to a DIY project, and that doesn’t just apply to homemade lockjaw toffee. When a watch is so well-made that it looks like one from a jewelry store, it is easy to keep quiet. [ColinMerkel] took many pictures of his fourth wristwatch attempt but “attempt” is his word because we call this a success. This time around he didn’t forget the crown for adjusting the time so all the pieces were in place.

His second “attempt” at wristwatch making was featured here and it had a classical elegance. Here, the proverbial game has been stepped up. Instead of using stock steel, the body is constructed of 303 stainless steel. The watch dial will definitely draw compliments if its DIY nature is revealed, which is equally mathematical and charming. Pictures of this process were enough to convey the build without words which is always a bonus if you only want a quick look or English isn’t your first choice for language.

Not only is [Colin] an upstanding horologist, he has a reputation with aftermarket door security and a looping guitar pedal.

Rotary Phones And The Birth Of A Network

July 26, 2017 by Al Williams 85 Comments

I can’t help but wonder how long it will be before the movie title “Dial M for Murder” becomes mysterious to most of the population. After all, who has seen a dial phone lately? Sure, there are a few retro phones, but they aren’t in widespread use. It may not be murder, but it turns out that the dial telephone has its roots in death — or at least the business of death. But to understand why that’s true, you need to go back to the early days of the telephone.

Did you ever make a tin can phone with a string when you were a kid? That dates back to at least 1667. Prior to the invention of what we think of as the telephone, these acoustic phones were actually used for specialized purposes.

We all know that [Alexander Graham Bell] made a working telephone over a wire, drawing inspiration from the telegraph system. However, there’s a lot of dispute and many others about the same time were working on similar devices. It is probably more accurate to say that [Bell] was the first to successfully patent the telephone (in 1876, to be exact).

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Dial Is A Simple And Effective Wireless Media Controller

January 17, 2015 by Rick Osgood 27 Comments

[Patrick] was looking for an easier way to control music and movies on his computer from across the room. There is a huge amount of remote control products that could be purchased to do this, but as a hacker [Patrick] wanted to make something himself. He calls his creation, “Dial” and it’s a simple but elegant solution to the problem.

Dial looks like a small cylindrical container that sits on a flat surface. It’s actually split into a top and bottom cylinder. The bottom acts as a base and stays stationary while the top acts as a dial and a push button. The case was designed in SOLIDWORKS and printed on a 3D printer.

The Dial runs on an Arduino Pro mini with a Bluetooth module. The original prototype used Bluetooth 2.0 and required a recharge after about a day. The latest version uses the Bluetooth low energy spec and can reportedly last several weeks on a single charge. Once the LiPo battery dies, it can be recharged easily once plugged into a USB port.

The mechanical component of the dial is actually an off-the-shelf rotary encoder. The encoder included a built-in push button to make things easier. The firmware is able to detect rotation in either direction, a button press, a double press, and a press-and-hold. This gives five different possible functions.

[Patrick] wrote two pieces of software to handle interaction with the Dial. The first is a C program to deal with the Bluetooth communication. The second is actually a set of Apple scripts to actually handle interaction between the Dial and the various media programs on his computer. This allows the user to more easily write their own scripts for whatever software they want. While this may have read like a product review, the Dial is actually open source! Continue reading “Dial Is A Simple And Effective Wireless Media Controller” →

Papercraft Dial Is The Slide-ruler Of Current Limiting Resistors

January 14, 2013 by Mike Szczys 33 Comments

led_resistor_dial_39

This paper dial makes selecting current limiting resistors a snap. [Giorgos Lazaridis] came up with the tool, which he describes in detail in the Worklog tab of his writeup. If you want one of your own he also posted a PDF which you can print, cut, and tack together.

At this point we can calculate resistor values for LED circuits without looking at reference material. But it wasn’t always like that. This wheel will be a fantastic tool for those just starting out in hobby electronics who are trying to grasp the theory behind lighting up a simple project. The outer wheel references the source voltage, with the inner being a gauge of forward voltage across the LED(s). Line those two values up and you can read the optimal resistor value in the window seen to the right. But wait, there’s more! As you can see in the video after the break the opposite face of the dial also includes a window which will tell you the power dissipation so that you may choose a properly rated resistor. Slick!

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