Current Sink Keeps The Smoke In

June 1, 2017 by Bryan Cockfield 11 Comments

One of the most versatile tools on anyone’s work bench, at least as far as electrical projects are concerned, is a power supply. Often we build our own, but after we’ve cobbled together some banana jacks with a computer’s PSU or dead-bug soldered a LM317 voltage regulator to a wall wart, how will that power supply perform? Since it’s not desirable to use a power supply that’ll let the smoke out of everything it powers (or itself, for that matter) a constant current sink, or load, can help determine the operating limits of the power supply.

[electrobob] built this particular current sink from parts he had lying around. The theory of a constant current sink is relatively straightforward so it’s easily possible to build one from parts out of the junk drawer, provided you can find a few transistors, fuses, an op amp, and some heat sinks. The full set of schematics that [electrobob] designed can be found on his main project page. He’s also gone a step further with this build as well, since he shorted out his first prototype and destroyed some of the transistors. But, using a few extra transistors in his design also improves the safety and performance of the load, so it’s a win-win.

This constant current load also has the added feature of being able to interface with a waveform generator (an Analog Discovery, specifically) and as a result can connect and disconnect the load quickly. If you aren’t in need of an industrial-grade constant current sink and you have some spare parts lying around, this would be a great one to have around the work bench.

VGA Output On A Freescale

February 26, 2016 by Bryan Cockfield 5 Comments

Even though VGA is an outdated and becoming somewhat deprecated, getting this video output running on non-standard hardware is a rite of passage for some hackers. [Andrew] is the latest to take up the challenge. He got VGA output on a Freescale i.MX233 and also got some experience diving into the Linux kernel while he was at it.

The Freescale i.MX233 is a single-board computer that is well-documented and easy to wire up to other things without specialized hardware. It has video output in the form of PAL/NTSC but this wasn’t quite enough for [Andrew]. After obtaining the kernel sources, all that’s needed is to patch the kernel, build the kernel, and build a custom DAC to interface the GPIO pins to the VGA connector.

The first thing that [Andrew] did was load up the Hackaday home page, which he notes took quite a while since the i.MX233 only runs at 454 MHz with just 64 MB of RAM. While our retro page may have loaded a little faster, this is still an impressive build and a great first step to exploring more of the Linux kernel. The Freescale i.MX233 is a popular chip for diving into Linux on single-board computers, and there’s a lot going on in that community. There are some extreme VGA hacks out there as well if that’s more your style.

Sci-Fi Contest Roundup: The Valve Universe

April 21, 2014 by Brian Benchoff 6 Comments

While most of the entries to our Sci-Fi contest come from movies and TV shows, a select few are based on the Valve universe, including a few builds based on Portal and Team Fortress 2.

Deadly neurotoxin

Who wouldn’t want a gigantic articulated sociopathic robot hanging around? Two groups are building a clone of GLaDOs from the Portal series. and already the builds look really great.

[AmarOk], developed an open-source personal assistant called RORI that intends to be a more helpful version of GLaDOs, without all the testing and killing. He, along with [Peterb0y] and [n0m1s] are turning this personal assistant software into a GLaDOs replica.

Taking a slightly different tack, [Eric] and [jjyacovelli] built a GLaDOs-like robot with a camera in the ‘face’. This camera connects to a Google Glass and tracks the user’s head movements. There’s also a Nerf gun attached to the end of the robot body, triggered by double winking. Yep, it’s a heads-up display GLaDOs, perfect for punishing your test subjects.

Heavy load comin’ through!

Sentry

Not to be out done by a malevolent, hyper-intelligent artificial intelligence, [Tyler] and [Ryan] are building the cutest gat’ dern weapon in all of west Texas. It’s the level one sentry from Team Fortress 2, and the guys are turning one into a paintball sentry.

The TF2 sentry is a cute little bugger capable of motion tracking and perimeter defense, filling enemies with lead should they ever come too close.

While the end result probably won’t be as large or as heavy as the “official” real-life turret, a smaller table-top sized model is probably a little more practical. Even if it doesn’t live up to expectations, upgrading the sentry is simply a matter of whacking it with a wrench a few times.

There’s still time for you to cobble together an awesome Sci-Fi project and have a chance to win some awesome prizes.

Wall-wart Retrofitted With A High-power LED Supply Circuit

February 13, 2013 by Mike Szczys 10 Comments

high-power-LED-wall-wart-supply

This custom circuit board picks up some of the pieces from a wall wart to drive a high-power LED. The basic concept is to keep the high-voltage components and swap out the low voltage ones for parts that will be able to drive the 10W load.

The PCB is custom designed, but you can see that it was shaped to match the wall wort’s original board. To the right is the original 500mA transformer. The low-voltage side uses an LM393 because of its dual-comparators. This provides feedback for both current and voltage and is a perfect compliment for the TOP242. We haven’t seen that part before, but [Mincior] says that it’s nice for this application as it has safety features that lock down the chip if power or temperature are above spec. Once the replacement is nestled inside of the plastic case it looks stock and makes sure that your custom LED fixtures will stand the test of time safely.

Adding A Lot Of Twinkle To This Rebar Sculpture

March 7, 2012 by Mike Szczys 11 Comments

Blinky lights have a way of attracting attention and that’s exactly what the members of the Maui Makers hackerspace were shooting for. The sculpture above is the logo for the Source festival, a Burning Man inspired music gathering in the Aloha state. For this year’s festival they went crazy, installing twelve meters of RGB LED strip controlled by seven Arduino boards.

The goal was to make the twelve-foot tall sculpture into a lighted interactive showpiece. In addition to the LEDs it includes a microphone, capacitance sensors, Bluetooth connectivity, and a piezo speaker. There’s one Arduino to rule them all, with another Teensy controller to drive an LCD display in the control box, and five Teensy boards to address the LED strips. They grabbed [Bill Porter’s] Easy Transfer library to facilitate communication between the microcontrollers (his libraries are becoming popular, we just saw his mp3 shield library used in another project on Tuesday).

The code which drives the LED animations is based on some Adafruit examples. We really enjoy the waving flag effect seen in the clip after the break.

Continue reading “Adding A Lot Of Twinkle To This Rebar Sculpture” →

Lolo’s (perfect Moment) Alarm Clock

July 17, 2010 by Jakob Griffith 20 Comments

[youtube http://www.youtube.com/watch?v=CphsgESZGcE&feature=player_embedded%5D

It seems everybody has a different interpretation of the perfect alarm clock. [Loic Royer’s] alarm clock is not the loudest, or the smartest, but does have some interesting features. By monitoring several environmental factors like temperature, air quality, humidity, dew point, and your own sleep patterns, this alarm clock can determine the best moment in the morning to wake you up.

The main sensor is a wireless accelerometer with the theory being: the more you move in your sleep, the closer you are to a conscious state. The other sensors assist in picking the perfect moment, and awaken you with the sound of birds chirping.

For now all we have is the source code and the list of hardware, but for anyone wanting to try, a circuit diagram wouldn’t be too hard to figure out on your own. Check after the rift for some more videos. Continue reading “Lolo’s (perfect Moment) Alarm Clock” →

Need To Source Nixie Tubes?

December 18, 2009 by Mike Szczys 17 Comments

Nixie tubes make for fun projects but the fun can’t start until you get your hands on the hardware. Well, [Dieter’s] got you covered with his one-stop repository on Nixie tubes and where to get them. We know that Woz’s watch isn’t currently available because of a lack of tiny tubes an obsolete accelerometer. Ladyada’s Ice Tube Clock depends on a rare 8-digit VFD tube. But you can get around parts obsolescence by adapting these designs for an available replacement. So when you take on the Dekatron Timer or a Bottled Nixie Clock you’ll know where to turn for the goods.

Update: Our mistake about Woz’s watch. It wasn’t a tube shortage that put it out of production.

[Thanks Aaron]