NYC Resistor shows you how to have some fun with electronics from the junk bin. Their post called The Joy of Dumping encourages you to look around for older memory chips and see what they’ve been hiding away for all these years.
The targets of their hunt are EPROM chips. Note the single ‘E’. These are Erasable Programmable Read-Only Memory chips, and predate EEPROM which adds “Electrically” to the beginning of the acronym. You used to use a UV light source to erase the older types of memory. In fact we’ve seen some EPROM erasers as projects from time to time. These shouldn’t be too hard to find as they were prevalent as cheap storage back in the 1980’s.
If the quartz window on the top of the chips has been shielded from ambient UV light, you should still be able to read them and it’s as easy as hooking up your Arduino. Is it useful? Not really, but it still can be neat to interface with what might otherwise never make its way back out of the junk box.
Whether you’re trying to light your path, build your own night vision, or do some tanning at home, this flashlight has you covered. [David Prutchi] designed the high power flashlight with three swappable heads.
He built the base unit out of aluminum pipe. It’s got plenty of room for the four 9V batteries that act as the power source. The driver circuit is just a bit smaller than one of those batteries, and to bring the whole thing together [David] and his helper added a potentiometer, toggle switch, and quick connector which makes head swaps a breeze. The heads themselves are all LED based, with one for visible light, another for infrared, and the final module outputs ultraviolet. We joke about tanning with it, but at 10 Watts you should be more worried about accidental damage to your vision.
The finished product is shown checking the security ink on some Canadian Currency. This would also make a nice secondary light source for your night vision monocle.
[mike6789k] wanted to spice up his dorm room, so he built a cool music synchronized light show that struck us as being very well thought out. We have seen similar music-based visualizations before, but they tend to be pretty basic, relying on volume more than actual audio frequencies to trigger the lighting.
[mike6789k] didn’t want to build “just another” synchronized light show, and his all-analog approach gives a true representation of the music being played instead of just flashing lights along with the beat. Using a trio of simple filters, he broke the audio signals down into three distinct frequency bands before being driven through a high gain transistor to power a set of LEDs.
We were pretty impressed at how bright the display was given that he is using UV LEDs, but the 1W diodes seem to have no problem lighting up the place when aimed through the UV-reactive water, as you can see in the video below.
If you’re looking to make something similar for your next party, the folks over at Buildlounge were able to wrangle a schematic out of [mike6789k], which you can find here.
Continue reading “Slick music synchronized light show uses UV LEDs and water”
[David] has always wanted use UV LEDs to write on a phosphorescent surface ever since saw an article about it on Make. He accidentally purchased UV LEDs when he meant to buy purple ones, so he figured that his mistake was all the reason he needed to give UV light writing a try.
He built a PIC16F628 UV POV board using the LEDs, and while manually swiping the writer across various glow in the dark surfaces was cool, he wanted to keep the POV board stationary, moving the writing medium instead. He bought some phosphorescent vinyl, but found that it wasn’t too flexible, meaning he could not use a conveyor belt approach for his display. One day it dawned on him that a vinyl ring might work pretty well, and using a motor from an old cassette player, he constructed the UV writer you see above.
It seems to work pretty well despite a small flaw in the UV ring, and while [David] is happy with the results, he already has plenty of ideas in mind for the second revision.
Check out the video of his UV light ring in action after the jump.
Continue reading “Spinning UV light writer”
Some projects benefit greatly from the parts a builder is able to find. Take this UV exposure bed for photo-resist copper clad boards (translated). It looks like a commercial product, but was actually built by [TabascoEye] and his fellow hackers.
The main sources for parts were a flatbed scanner (which acts as the case) and two self-tanning lamps that use UVA flourescent bulbs. By sheer luck the bulbs and their reflectors are exactly the right size to fit into the top and bottom cavities of the scanner. The control hardware centers around an ATtiny2313 micorocontroller, which takes input from a clickable rotary encoder, and displays exposure information on a character LCD. The finished product deserves a place right next to other professional-looking exposure boxes that we’ve looked at.
A few years back [Bunnie] took a crack at cracking the security fuses on a PIC microcontroller. Like most of the common 8-bit microcontrollers kicking around these days, the 18F1320 that he’s working with has a set of security fuses which prevent read back of the flash memory and EEPROM inside. The only way to reset those security fuses is by erasing the entire chip, which also means the data you sought in the first place would be wiped out. That is, if you were limited to using orthodox methods.
[Bunnie] had a set of the chips professionally uncapped, removing the plastic case without damaging the silicon die inside. He set to work inspecting the goodies inside with an electron microscope and managed to hammer out a rudimentary map of the layout. Turns out that flash memory can be erased with ultraviolet light, just like old EPROM chips. Microchip thought of that and placed some shielding over the security fuses to prevent them being reset in this manner. But [Bunnie] managed to do so anyway, creating an electrical tape mask to protect the rest of the data stored in the chip while bouncing UV light underneath the shielding at an angle.
Want to uncap some chips of your own without enlisting the help of others? Give this method a try.
[via Dangerous Prototypes]
This water sculpture can stop drops of water in mid-air. This is accomplished by flashing LEDs to illuminate the droplets at just the right time. But it’s not limited to blinky lights alone. The top of the frame has eight nozzles, each fed by its own pump. An Arduino controls the pumps and the lights making it possible to create different motion effects by adjusting how events line up. For instance, the image above shows just two of the water nozzles on, but in the video after the break it appears one is dripping downward while the other is dripping upward.
Alas, there’s few build details for this but the source code is available for downloading. If we were going to build one of these ourselves we’d probably try to regulate the drips using some solenoids built from scratch. How would you do it? Leave your ideas in the comments.
Continue reading “Water droplet sculpture using LEDs and Arduino”