LiquidWatch Is Dripping With Style

December 26, 2017 by 13 Comments

Some of the entries for the 2017 Coin Cell Challenge have already redefined what most would have considered possible just a month ago. From starting cars to welding metal, coin cells are being pushed way outside of their comfort zone with some very clever engineering. But not every entry has to drag a coin cell kicking and screaming into a task it was never intended for; some are hoping to make their mark on the Challenge with elegance rather than brute strength.

A perfect example is the LiquidWatch by [CF]. There’s no fancy high voltage circuitry here, no wireless telemetry. For this entry, a coin cell is simply doing what it’s arguably best known for: powering a wrist watch. But it’s doing it with style.

The LiquidWatch is powered by an Arduino-compatible Atmega328 and uses two concentric rings of LEDs to display the time. Minutes and seconds are represented by the outer ring of 60 LEDs, and the 36 LEDs of the inner ring show hours. The hours ring might sound counter-intuitive with 36 positions, but the idea is to think of the ring as the hour hand of an analog watch rather than a direct representation of the hour. Having 36 LEDs for the hour allows for finer graduation than simply having one LED for each hour of the day. Plus it looks cool, so there’s that.

Square and round versions of the LiquidWatch’s are in development, with some nice production images of [CF] laser cutting the square version out of some apple wood. The wooden case and leather band give the LiquidWatch a very organic vibe which contrasts nicely with the high-tech look of the exposed PCB display. Even if you are one of the legion that are no longer inclined to wear a timepiece on their wrist, you’ve got to admit this one is pretty slick.

Whether you’re looking to break new ground or simply refine a classic, there’s still plenty of time to enter your project in the 2017 Coin Cell Challenge.

Watch Video On A Oscilloscope With An ESP32

December 23, 2017 by 18 Comments

[bitluni] got a brand new scope, and he couldn’t be happier. No, really — check the video below; he’s really happy. And to celebrate, he turned his scope into a vector display using an ESP32.

Using a scope in X-Y mode is nothing new, of course. The technique is used to display everything from Lissajous patterns from an SDR to bouncing balls from an analog computer. Taken on as more of an exercise to learn how to use his new tool than a practical project, [bitluni]’s project starts by using two DACs on an ESP32 to create simple Lissajous patterns to learn about the scope’s controls. Next he built some code to display 3D point clouds, but learned that the native DAC code wasn’t up to the job. A little hacking improved the speed 27-fold, which was enough for great 3D images and live video from an I²S camera module. The latter was accomplished by grabbing frames from the camera and rendering them pixel by pixel, CRT style. The results are pretty clean, and there’s a lot to be learned about both using scopes as X-Y displays and tweaking the ESP32 for maximum performance.

Need more background on the ESP32? Start by checking out these ESP32 tutorials.

 

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A Watch Only A Ham Can Use

December 19, 2017 by 17 Comments

We’re not sure what to make of this one. With the variety of smartwatches and fitness trackers out there, we can’t be surprised by what sort of hardware ends up strapped to wrists these days. So a watch with an RPN calculator isn’t too much of a stretch. But adding a hex editor? And a disassembler? Oh, and while you’re at it, a transceiver for the 70cm ham band? Now that’s something you don’t see every day.

The mind boggles at not only the technical prowess needed to pull off what [Travis Goodspeed (KK4VCZ)] calls the GoodWatch, but at the thought process that led to all these features being packed into the case of a Casio calculator watch. But a lot of hacking is more about the “Why not?” than the “Why?”, and when you start looking at the feature set of the CC430F6137 microcontroller [Travis] chose, things start to make sense. The chip has a built-in RF subsystem, intended no doubt to enable wireless sensor designs. The GoodWatch20 puts the transceiver to work in the 430-MHz band, implementing a simple low-power (QRP) beacon. But the real story here is in the hacks [Travis] used to pull this off, like using flecks of Post-It notes to probe the LCD connections, and that he managed to stay within the confines of the original case.

There’s some real skill here, and it makes for an interesting read. And since the GoodWatch is powered by a coin cell, we think it’d be a great entry for our Coin Cell Challenge contest.

[via r/AmateurRadio]

CosmicWatch muon detector

Make A Cheap Muon Detector Using Cosmicwatch

November 27, 2017 by 13 Comments

A little over a year ago we’d written about a sub $100 muon detector that MIT doctoral candidate [Spencer Axani] and a few others had put together. At the time there was little more than a paper on arxiv.org about it. Now, a few versions later they’ve refined it to the level of a kit with full instructions for making your own under the banner, CosmicWatch including PCB Gerber files for the two surface mount boards you’ll need to assemble.

What’s a muon? The Earth is under constant bombardment from cosmic rays, most of them being nuclei expelled from supernova explosions. As they collide with nuclei in our atmosphere, pions and kaons are produced, and the pions then decay into muons.  These muons are similar to electrons, having a +1 or -1 charge, but with 200 times the mass.

This pion-to-muon decay happens higher than 10 km above the Earth’s surface. But the muons have a lifetime at rest of 2.2 μs. This means that the number of muons peak at around 10 km and decrease as you go down. A jetliner at 30,000 feet will encounter far more muons than will someone at the Earth’s surface where there’s one per cm2 per minute, and the deeper underground you go the fewer still. This makes them useful for inferring altitude and depth.

Muon detector
How it works

How does CosmicWatch detect these muons? The working components of the detector consist of a plastic scintillator, a silicon photomultiplier (SiPM), a main circuit board which does signal amplification and peak detection among other things, and an Arduino nano.

As a muon passes through the scintillating material, some of its energy is absorbed and re-emitted as photons. Those photons are detected by the silicon photomultiplier (SiPM) which then outputs an electrical signal that is approximately 0.5 μs wide and 10-100 mV. That’s then amplified by a factor of 6. However, the amplified pulse is too brief for the Arduino nano and so it’s stretched out by the peak detector to roughly 100 μs. The Arduino samples the peak detector’s output and calculates the original pulse’s amplitude.

Their webpage has copious details on where to get the parts, the software and how to make it. However, they do assume you can either find a cheap photomultiplier somewhere or buy it in quantities of over 100 brand new, presumably as part of a school program. That bulk purchase makes the difference between a $50 part and one just over $100. But being skilled hackers we’re sure you can find other ways to save costs, and $150 for a muon detector still isn’t too unreasonable.

Detecting muons seems to have become a thing lately. Not too long ago we reported on a Hackaday prize entry for a detector that uses Russian Geiger–Müller Tubes.

Mega Game & Watch Octopus

Mega Game & Watch: True Multiplayer Game

November 16, 2017 by 8 Comments

Today we’re used to handheld game consoles like the Nintendo Switch, that let you roam around in 3D worlds which include not only 3D players but more terrain than many people walk around in real life in a week. But back in the early 1980s Nintendo’s handheld offering was the Game & Watch, which used a segmented LCD display. An entire segment could be used to represent the player, with player segments spread throughout the display. To move the player, the previous player segment would be turned off while another adjacent one would be on. That also meant that a console could play only one game. Despite these limitations they were very popular for their time.

[Thomas Tilley] decided to improve on the old Game & Watch in a different way, by making it bigger, much bigger. So big in fact that even many teenage players can’t reach both the button to move left and the button to move right in time, turning it into a highly co-operative two-player game. Judging by the video below, that made playing it double the fun. The game he chose to tackle is the Game & Watch Octopus, or Mysteries of the Sea and Mysteries of the Deep in the UK.

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80’s Smartwatch Finally Plays Tetris

November 14, 2017 by 19 Comments

While the current generation of smartwatches have only been on the market for a few years, companies have been trying to put a computer on your wrist since as far back as the 80s with varying degrees of success. One such company was Seiko, who in 1984 unveiled the UC-2000: a delightfully antiquated attempt at bridging the gap between wristwatch and personal computer. Featuring a 4-bit CPU, 2 KB of RAM, and 6 KB of ROM, the UC-2000 was closer to a Tamagotchi than its modern day counterparts, but at least it could run BASIC.

Dumping registers

Ever since he saw the UC-2000 mentioned online, [Alexander] wanted to get one and try his hand at developing his own software for it. After securing one on eBay, the first challenge was getting it connected up to a modern computer. (Translated from Russian here.) [Alexander] managed to modernize the UC-2000’s novel induction based data transfer mechanism with help from a ATtiny85, which allowed him to get his own code on the watch, all that was left was figuring out how to write it.

With extremely limited published information, and no toolchain, [Alexander] did an incredible job of figuring out the assembly required to interact with the hardware. Along the way he made a number of discoveries which set his plans back, such as the fact that there is no way to directly control individual pixels on the screen; all graphics would have to be done with the built-in symbols.

The culmination of all this hard work? Playing Tetris, naturally. Though [Alexander] admits that limitations of the device’s hardware meant the game had to be simplified a bit, he’s almost certainly having more fun than any of the UC-2000’s original owners did with this device. He’s setup a GitHub repository for anyone who wishes to join him in this brave new world of vintage wrist computing.

[Alexander] isn’t the only one experimenting with fringe wearable computers. We’ve seen our fair share of interesting smartwatches, featuring everything from novel input methods to complete scratch-builds.

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