Day: October 1, 2019

How Do Those Component Testers Work?

October 1, 2019 by 12 Comments

Most people have at least seen those cheap component testers you can buy on the Chinese websites for $10 or so. If you haven’t seen them before, they usually have some kind of multi pin socket. You put a component in the socket and it will identify — with a push of a button — what the part is, which pin is which, and the value of the part. For example, you can insert a resistor, a capacitor, an inductor, a diode, or a transistor and get a readout of which pin is which. It seems like magic, but [Andreas Spiess] did the research on how it all works and summed up his findings in a recent video.

[Andreas] even quotes our earlier post on the topic and, as we did, dug into the original developers of the device which has been cloned over and over by Chinese sellers. Although there have been some divergence with all the different versions, the basic idea is the same. An AVR CPU uses some analog and digital trickery to make a lot of different measurements.

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Bouncing Signals Off The Moon

October 1, 2019 by 28 Comments

One of the great things about ham radio is that isn’t just one hobby. Some people like to chit chat, some like to work foreign countries, some prepare for emergencies, and there are several space-related activities. There are hundreds of different kinds of activities to choose from. Just one is moonbounce, and [Ham Radio DX] decided to replicate a feat many hams have done over the years: communicate with someone far away by bouncing signals from the moon.

The set up is pretty sophisticated but not as bad as you might imagine. You can see that they spend a lot of time getting the equipment aligned. A known reference point helps them set the position of the antenna. A GPS keeps both stations in sync for frequency and time.

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Copper Coil Lamp Built With 3D Printed Tools

October 1, 2019 by 7 Comments

3D printing is a great way to create complex geometric forms. However, it can be very slow, and parts may lack strength compared to other alternatives. There are other ways to take advantage of this technology however, as shown in the build of this tidy voronoi lamp. 

The lamp is so-called for its voronoi-patterned base, named after the mathematical concept. 3D printing is used to create the base, which would be very difficult to create with traditional subtractive machining methods. A copper coil is then used to give the lamp some height, as well as act as protection for the filament bulb. Here, 3D printing helps out in a different way, being used to create a jig to allow the copper to be quickly wound into an accurate coil shape. The coil also serves to act as a conduit for the mains wiring, giving the lamp a neat finished appearance.

The project goes to show that even if 3D printing is appropriate to produce your final parts, it may be of help to create useful jigs or tools to get the job done. We’ve even seen similar applications before in the microcontroller space!

Monochrome CRT And Liquid Crystal Shutter Team Up For Color Video

October 1, 2019 by 21 Comments

If you were tasked with designing a color video monitor, it’s pretty clear how you’d go about it. But what if you’d been asked to do so 20 years ago? Would it have been a cut and dried from an engineering standpoint? Apparently not, as this hybrid LCD-CRT video monitor demonstrates.

We’d honestly never heard of this particular design, dubbed “LCCS”, or liquid crystal color shutter, until [Technology Connections]’ partial teardown of the JVC monitor and explanation of its operation. The idea is simple and hearkens back to the earliest days of color TV in the United States, when broadcasters were busy trying to bring color to a monochrome world in a way that would maximize profits. One scheme involved rotating a color wheel in front of the black-and-white CRT and synchronizing the two, which is essentially what’s happening in the LCCS system. The liquid crystal panel cycles between red, blue, and green tints in time with the CRT’s images behind it, creating a full-color picture. “But wait!” you cry. “Surely there were small color CRTs back in the year 2000!” Of course there were, but they kind of sucked. Just look at the comparison of a color CRT and the LCCS in the video below and you’ll see why this system carved out a niche in the pro video market, especially for video assist monitors in the days before digital cinematography. A similar system was used by Tektronix for color oscilloscopes, too.

As usual, [Technology Connections] has managed to dig up an interesting bit of the technological fossil record and present it in a fascinating way. From video on vinyl to 1980s copy protection to the innards of a toaster, we enjoy the look under the hood of forgotten tech.

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A Retro Gaming Console For The New Generation

October 1, 2019 by 6 Comments

Ostensibly the ESPboy is an open-source hackable game engine built as an IoT platform for STEM education and play, but there’s no way [RomanS] could have been inspired by anything other than retro gaming consoles from the near past. For anyone who grew up playing with Tamagotchi pets or Palm Pilots, this project is going to be a major throwback.

The Saint Petersburg-based microcontroller hobbyist utilizes a ESP8266 microcontroller to build a series of modules for different game play modes, including a TFT display, GSM phone, MP3 player, GPS navigator, FM radio, and keyboard module. He has plans to build even more modules, including a LoRa messenger and thermal camera, to really expand the system’s capabilities.

Since the board has built-in WiFi, firmware can be uploaded to the device without a wired connection and compiler. The nature of the project makes the board compatible with the Arduino IDE and Micropython, which makes hacking the software even easier.

A TP4056 battery charging module charges the LiPo, although depending on the battery capacity, the charging current (set by the R3 resistor on the controller) does require some change. A MCP4725 I2C DAC is used for smooth driving the LCD’s backlight. In order to extend the battery life, the battery controller uses sleep mode to periodically wake up to measure and send data, which allows it to extend its battery life without external power. There’s also transistor driven buzzers that provide a little extra feedback to the user when playing games, complete with a variable resistor to adjust the sound volume.

A number of free pins run along the periphery for connecting to other modules, including pins for GPIO extension, sensor adapters, connectors to addressable LEDs, and an extension slot for actuators. For anyone interested in making their own version of the ESPboy, the PCB schematics are accessible online.

Projects like the Arduboy have shown that a small microcontroller-based game system can be equal parts fun and educational, so we’ve been excited to see more of these types of projects popping up during the course of the 2019 Hackaday Prize.

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Fried Desk Lamp Reborn: How To Use ESP8266 To Build Connected Devices

October 1, 2019 by 9 Comments

Some hacks are born of genius or necessity, and others from our sheer ham-fisted incompetence. This is not a story about the first kind. But it did give me an excuse to show how easy it is to design WiFi-connected devices that work the way you want them to, rather than the way the manufacturer had in mind.

It started out as a sensible idea – consumer electronics in Vietnam have many different electric plug types for mains AC power: A, C, G, F, and I are fairly present, with A and C being most common. For a quick review of what all those look like, this website sums it up nicely. There are universal power adapters available of course, but they tend to fit my most common type (C) poorly, resulting in intermittent power loss whenever you sneeze. So I figured I should replace all the plugs on my devices to be A-type (common to those of you in North America), as it holds well in all the power bar types I have, mainly leftover server PDUs.

This was very straightforward until I got to my desk lamp. Being a fancy Xiaomi smart lamp, they had opted to hide a transformer in the plug with such small dimensions that I failed to notice it. So instead of receiving a balmy 12 volts DC, it received 220 volts AC. With a bright flash and bang, it illuminated my desk one final time.

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A Useless Tomb Of Eternal Doom

October 1, 2019 by 10 Comments

It’s officially October, and that means we can start unleashing the Halloween hacks. Take for example this restless skeleton that master automaton maker [Greg Zumwalt] has doomed to spend eternity inside of a useless box. If that wasn’t enough to wake the dead, every time some joker pushes the button, these blinky lights come on. Hey, at least there’s no opera music.

The ironic thing about useless machines is that there are a ton of ways to make them. This spooktacular Halloween-themed do-nothing box doesn’t use a microcontroller, or even a 555 — it’s purely electromechanical. When the button is pressed, two AAAs power a small gear motor that simultaneously lifts the lid, raises the dead, and twists him a quarter turn so he can close the lid and put himself back to eternal rest.

The intricately-printed skeleton doesn’t really push the button — he’s far too dead and frail for that. The gear motor also turns a dual-lobe cam that activates a pair of roller switches that handle the candles and lower Mr. Bones back into his crypt. Clear as blood? Skitter past the break for a closer look at the mechanism.

Halloween or not, we love a good useless machine around these parts. Here’s one that incorporates a real candle and who could forget this octo-switched beast?

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