Roll Up Your Sleeve, Watch A Video With This Smart Watch Forearm Projector

April 25, 2018 by Dan Maloney 35 Comments

We’re all slowly getting used to the idea of wearable technology, fabulous flops like the creepy Google Glass notwithstanding. But the big problem with tiny tech is in finding the real estate for user interfaces. Sure, we can make it tiny, but human fingers aren’t getting any smaller, and eyeballs can only resolve so much fine detail.

So how do we make wearables more usable? According to Carnegie-Mellon researcher [Chris Harrison], one way is to turn the wearer into the display and the input device (PDF link). More specifically, his LumiWatch projects a touch-responsive display onto the forearm of the wearer. The video below is pretty slick with some obvious CGI “artist’s rendition” displays up front. But even the somewhat limited displays shown later in the video are pretty impressive. The watch can claim up to 40-cm² of the user’s forearm for display, even at the shallow projection angle offered by a watch bezel only slightly above the arm — quite a feat given the irregular surface of the skin. It accomplishes this with a “pico-projector” consisting of red, blue, and green lasers and a pair of MEMS mirrors. The projector can adjust the linearity and brightness of the display to provide a consistent image across the uneven surface. An array of 10 time-of-flight sensors takes care of watching the display area for touch input gestures. It’s a fascinating project with a lot of potential, but we wonder how the variability of the human body might confound the display. Not to mention the need for short sleeves year round.

Need some basics on the micro-electrical mechanic systems (MEMS) behind the pico-projector in this watch? We’ve got a great primer on these microscopic machines.

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Video Quick-Bit: Numitrons And Infinite Build Volumes

April 25, 2018 by Brian Benchoff 6 Comments

Majenta Strongheart takes a look at a couple of cool entries from the first round of the 2018 Hackaday Prize:

This is an infinite 3D printer. The Workhorse 3D is the way we’re going to democratize 3D printing. The Workhorse 3D printer does this by adding a conveyor belt to the bed of a 3D printer, allowing for rapid manufacturing, not just prototyping. [Swaleh Owais] created the Workhorse 3D printer to automatically start a print, manufacture an object, then remove that print from the print bed just to start the cycle all over again.

Check out this Numitron Hexadecimal Display Module from [Yann Guidon]. [Yann] is building an entire computer, from scratch, and he needs a way to display the status of various bits on a bus. The simplest way to do this is with a few buffer chips and some LEDs, but that’s far too easy for [Yann]. He decided to use Numitron tubes to count bits on a bus, from 0 to F. Instead of microcontrollers, he’s using relays and diode steering to turn those segments of the Numitron on and off.

Browse all of the entries here. Right now, we’re in the Robotics Module Challenge part of the Hackaday Prize, where twenty incredible projects will win one thousand dollars and move on to the final part of the Hackaday Prize where one lucky winner will win fifty thousand dollars for building awesome hardware. If that’s not incredible, I don’t know what is.

Adventures In Gas Filled Tube Arrays

April 25, 2018 by Brian Benchoff 11 Comments

Vacuum tubes are awesome, and Nixies are even better. Numitrons are the new hotness, but there’s one type of tube out there that’s better than all the rest. It’s the ИГГ1-64/64M. This is a panel of tubes in a 64 by 64 grid, some with just green dots, some with green and orange, and even a red, green, blue 64 by 64 pixel matrix. They’re either phosphors or gas-filled tubes, but this is the king of all tube-based displays. Not even the RGB CRTs in a Jumbotron can match the absurdity of this tube array.

[Muth] got his hands on a few of these panels, and finally he’s displaying images on them. It’s an amazing project that involved finding the documentation, translating it, driving the tubes with 360 Volts, and figuring out a way to drive 128 inputs from just a few microcontroller pins.

First, the power supply. These panels require about 360 Volts to light up. This is significantly higher than what would usually be found in a Nixie clock or other normal tube-based display. That’s no problem, because a careful reading of the datasheet revealed a circuit that brings a normal-ish 180 Volt Nixie power supply up to the proper voltage. To drive these pixels, [Muth] settled on a rather large PIC18F microcontroller with eight tri-state buffers. The microcontroller takes data over a serial port and scans through the entire framebuffer. All in all, there are eight driver boards, 736 components, and 160 wires connecting everything together. It’s a lot of work, but now [Muth] has a 64×64 display that’s green and orange.

You can check out a ‘pixel dust’ demo of this display in action below.

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Litar: An Air Guitar Using LiDAR

April 25, 2018 by Steven Dufresne 6 Comments

This year, [Blecky’s] Hackaday Prize Entry is an air guitar which uses multiple LiDAR sensors to create the virtual strings. What’s also neat is that he’s using his own LiDAR sensor, the MappyDot Plus, an enhanced version of his 2017 Prize Entry, the MappyDot.

He uses a very clever arrangement of six sensors to get four virtual strings. Each sensor scans a 25-degree field of view. Three adjacent sensors are used to define a string, with the string being in the overlap of the outer two of those sensors. The middle sensor is used for the distance data.

For the chords, he started out using some commercially made joysticks but ran into some ergonomic issues. Also, the manufacturer was discontinuing the product, a no-no for an open source project. So he abandoned that approach and designed his own buttons. He came up with a PCB with a linear hall effect sensor and some springs on it. The button has a magnet attached to its underside and sits on the springs. That way he gets the press and can do vibrato as well.

He plans to use Bluetooth MIDI so that you can play the sound on a phone or laptop but for now he lights up an LED beside each sensor as you press the strings.

Retrotechtacular: Synchros Go To War (and Peace)

April 25, 2018 by Al Williams 41 Comments

Rotation. Motors rotate. Potentiometers and variable capacitors often rotate. It is a common task to have to rotate something remotely or measure the rotation of something. If I asked you today to rotate a volume control remotely, for example, you might offer up an open loop stepper motor or an RC-style servo. If you wanted to measure a rotation, you’d likely use some sort of optical or mechanical encoder. However, there’s a much older way to do those same tasks and one that still sees use in some equipment: a synchro.

The synchro dates back to the early 1900s when the Panama Canal used them to read and control valves and gates. These devices were very common in World War II equipment, too. In particular, they were often part of the mechanisms that set and read gun azimuth and elevation or — like the picture to the left — a position indication of a radar antenna. Even movie cameras used these devices for many years. Today, with more options, you don’t see them as much except in applications where their simplicity and ruggedness is necessary.

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Friday Hack Chat: Control Schemes For Robotics

April 25, 2018 by Brian Benchoff 1 Comment

The Hackaday Prize is in full swing if you haven’t heard. It’s the Academy Awards of Open hardware, and the chance for you — yes, you — to create the next great piece of hardware and a better future for everyone. Right now, we’re in the Robotics Module Challenge portion of the prize. This is your chance to build a module that could be used in robotics projects across the world! Show off your mechatronic skills and build a robotics module that’s transferable to other builds!

Not coincidentally, for this week’s Hack Chat, we’re talking all about Robotics Modules. We’re taking a deep dive into actuation and control schemes for robotics, and you’re invited to take part. Everyone wants affordable robotics, and stepper and servo motors are no longer the domain of high-budget industrial robots. Everyone can build a robot, but how do you do that? That’s what we’re going to find out this Friday in the Hack Chat!

Our guest for this week’s Hack Chat is [Ryan Walker]. He holds a diploma in Mechatronics and Robotics from BCIT. He’s worked on everything from prosthetics to industrial automation, and his current hobbies include designing and building control algorithms that drive electronics and enable cheap hardware to excel! If you want to learn about robotics, this is the Hack Chat for you.

In this chat, we’ll be talking about:

Control schemes
How to actuate your projects
Wheels, tweels, and ways to make your project move
Automating robotics

You are, of course, encouraged to add your own questions to the discussion. You can do that by leaving a comment on the Hack Chat Event Page and we’ll put that in the queue for the Hack Chat discussion.

Our Hack Chats are live community events on the Hackaday.io Hack Chat group messaging. This week is just like any other, and we’ll be gathering ’round our video terminals at noon, Pacific, on Friday, April 27th. Here’s a clock counting down the time until the Hack Chat starts.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io.

You don’t have to wait until Friday; join whenever you want and you can see what the community is talking about.

Reflow Rig Makes SMD Soldering A Wok In The Park

April 25, 2018 by Dan Maloney 14 Comments

For a DIY reflow setup, most people seem to rely on the trusty thrift store toaster oven as a platform to hack. But there’s something to be said for heating the PCB directly rather than heating the surrounding air, and for that one can cruise the yard sales looking for a hot plate to convert. But an electric wok as a reflow hotplate? Sure, why not?

At the end of the day [ThomasVDD]’s reflow wok is the same as any other reflow build. It has a heat source that can be controlled easily, temperature sensors, and a microcontroller that can run the proportional-integral-derivative (PID) control algorithm needed for precise temperature control. That the heating element he used came from an electric wok was just a happy accident. A laser-cut MDF case complete with kerf-bent joints holds the heating element, the solid-state relay, and the Arduino Nano that runs the show. A MAX6675 thermocouple amp senses the temperature and allows the Nano to cycle the temperature through different profiles for different solders. It’s compact, simple, and [ThomasVDD] now has a spare wok to use on the stove top. What’s not to like?

Reflow doesn’t just mean oven or hotplate, of course. Why not give reflow headlights, a reflow blowtorch, or even a reflow work light a try?