Shift Register Powered Realistic Candle Flicker

[Kevin Darrah] recently went out to dinner at a restaurant that was using some cheap LED candles (yuck) instead of the real thing. And in the true spirit of a hacker, he started to notice the patterns programmed into the fake flame repeat over and over again. And like any hacker might, his mind started to devise a better way.

Now’s the time where some of us lazy hackers might grab a microcontroller, and copy and paste in some pseudo-random number generating code you found on the Internet, but not [Kevin]. The basics of his hack uses two shift registers tied together that are fed a single clock signal, and also a latch signal that is slightly delayed version of the same signal made by a RC-time circuit.

The randomness of the output is created is by feeding back the outputs of the shift registers to an XOR gate. If you want to learn more about this, the technique it’s called a “linear feedback shift register“. It’s commonly used as a poor-man’s random number generator, although it’s not technically truly random, statistically it does a very good job. You can see the results in the video after the break where [Kevin] describes the circuit.  He wraps up the hack with a battery and solar charging circuit as well to make a completed project.

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CO2 Laser Decapping To Fix Soldering Mistake

[Carsten] messed up. He was soldering an ARM CPU onto a quadcopter board in haste, failed to notice that the soldering iron was turned up to eleven, and pulled some of the traces up off the PCB. In the process of trying to fix that, he broke three pins off of the 100-pin CPU. The situation was going from bad to worse.

Instead of admitting defeat, or maybe reflowing the CPU off of the board, [Carsten] lasered the epoxy case off of the chip down to the lead frame and worked a little magic with some magnet wire. A sweet piece of work, to be sure!

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Basically, It’s An ESP8266

Before the Arduino, there was the Parallax Basic Stamp. It was an easy-to-use PIC chip on a PCB that you programmed in BASIC — a story of those humble beginnings was published earlier this week. Before that, even, legions of small computers from TRS-80s to Commodore 64s and even Altairs were commanded primarily by the BASIC language. BASIC was easy to run on a small machine and very simple to learn. Old fashioned BASICs are difficult to use to write huge systems, but a lot of small computers aren’t going to run very large programs anyway.

The ESP8266 is more than a just a WiFi peripheral for a microcontroller. It is its own little computer in its own right. While it is common to run the “AT” firmware, Lua, or program the device yourself, you can now load the beast with a version of BASIC.

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3D Printed Mini Vectrex

With the more common availability of 3D printers, making miniature models of retro computer and video game gear is one way to nerd out and not fill the house up. [Jason] was looking around and noticed that no one has modeled the Vectrex video game system and stepped right in to fill the void with a working 3d printed miniature model of the unique early 80’s video game system.

For those who don’t live and breathe retro game systems, the Vectrex is a 1982 8 bit game machine unique in the fact that it comes with its own monochrome vector graphics CRT in the console. [Jasons] model features a 2.2 inch LCD with a SPI interface.

Emulation is powered by a VoCore SBC sporting a 360Mhz MIPS CPU and a modest 32 megs of ram, which is more than enough to handle the 8 bit math and wireframe graphics. The emulator used is a port 0f VECX with the display rerouted to the LCD screen instead of using standard SDL interfaces.

The case was modeled in Sketchup, and the whole lot is powered by a 3v3 lipo battery.  Join us after the break for a quick video of the mini model running the introduction to “Mine Storm” which was the onboard game original to the machine.

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Architecture of Radio

If Our Eyes Could See Wireless Signals, They Wouldn’t Look Like This.

A neat visualization of wireless signals was released last week showing off what our world might look like if we could see radio signals. While it’s an awesome visual effect, it’s really not what we would see. At least not with our puny human eyes.

The app uses data like WiFi hotspots, cell towers, and other wireless devices to create an augmented reality effect showing where the signals are propagating from. Site specific versions of the app also include the wired communication infrastructure as well to give a complete window into the science-fiction-sounding title of “infosphere”.

But like a user on Gizmodo commented, if we could actually see radio signals, they would just be flashes of light. Radio waves are just electromagnetic wavelengths longer than infrared light after all. Though if we could see those wavelengths, what’s the chance we have light speed vision too?

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Driving A 7 Segment LED Display From An FT232

Sometimes, a good hack is about using less rather than more. That’s the case with this neat tutorial from [Rahul.S] on driving a 7-segment LED display with an FT232. By using this cheap USB to serial controller, [Rahul.S] was able to drive the display directly without using a microcontroller, which keeps the component cost down.

He’s bit banging an octal buffer connected to the display. You may be surprised to find that the FT232 chips do have enough outputs to make this work. Rather than send serial data number to the display and have a controller convert this into a set of signals that make the number, this conversion is done by the PC, which then sends a signal that directly illuminates the appropriate parts of the LED. By using all of the available output lines of the FT232 (including ones like the RTS/CTS line that are usually used for signalling), [Rahul.S] was able to drive all seven of the elements and the decimal point.

Of course, cynics may argue that it would be simpler to use a cheap serial LCD display. That is true, but there is always something to be said for knowing how to do something yourself rather than letting others do it for you… Continue reading “Driving A 7 Segment LED Display From An FT232”

Hackaday Prize Semifinalist: Portable A/C

Many people with Multiple Sclerosis have sensitivity to heat. When the core body temperature of an MS sufferer rises, symptoms get worse, leading to fatigue, weakness, pain, and numbness. For his entry to the Hackaday Prize, [extremerockets] is finding a solution. He’s developing a wearable, personal cooling device that keeps the wearer at a comfortable temperature.

The device is based on a wearable shirt outfitted with small tubes filled with a cooling gel. This setup is extremely similar to the inner garments worn by astronauts on spacewalks, and is the smallest and most efficient way to keep a person’s core body temperature down.

Unlike a lot of projects dealing with heating and cooling, [extremerockets] isn’t working with Peltiers or thermoelectric modules; they’re terribly inefficient and not the right engineering choice for something that’s going to be battery-powered. Instead, [extremerockets] is building a miniature refrigeration unit, complete with a real refrigeration cycle. There are compressors, valves, and heat exchanges in this build, demonstrating that [extremerockets] has at least some idea what he’s doing. It’s a great project, and one we can’t wait to see a working prototype of.

The 2015 Hackaday Prize is sponsored by: