Tiny USB business card

[Frank Zhao] put together a USB business card. It’s even got the instructions printed right on the silk screen of the PCB explaining how it should be used. He based the design around an AVR ATtiny85 microcontroller. It runs the V-USB package that handles USB identification and communication protocols. The rest of the hardware is pretty standard, the uC draws power from the 5V USB rail, with a couple of 3.6V Zener diodes to drop the two data lines down to the proper level.

Once plugged in it waits until it detects three caps lock keypresses in a row, then spews a string of its own keypresses that type out [Frank's] contact information in a text editor window (video after the break). It’s not as reusable as the mass storage business card because [Frank] didn’t breakout the pins on controller. But we still enjoy seeing business cards that make you stand out.

This is a great project to tackle with your newly acquired AVR programming skills.

[Read more...]

Build a cutting laser from an old PC

[Drake Anthony] makes building a cutting laser from a PC look easy, and it seems like it actually is. Almost everything you need can be found in a dead desktop unit. The diode is pulled from a DVD writer (16x or faster), with the power supply unit, and heat sinks from the processor and GPU being used as well. You’ll also need a focusing lens (just a few dollars), some thermal glue, an LM317, a resistor, and a pair of protective goggles matching the laser diode’s wavelength.

He fits the diode into the lens, then glues the assembly into a hole drilled through the processor heat sink. A driver is built using the LM317 variable regulator, resistor, power supply, and the GPU heat sink to keep things cool. Check out the video after the break to see the laser cutting tape, burning plastic, and lighting matches. [Read more...]

Laser mic makes eavesdropping remarkably simple

Here’s a surprisly simple way to build yourself a laser-based listening device. It consists of two modules, a transmitter and a receiver. The transmitter is a set of lasers, one is visible red for aiming, and the other is infrared for measuring the vibration of a surface. Point the transmitter at the window of the room you want to listen in on and the laser can be reflected back to the receiver. The receiver module has a phototransistor to pick up the infrared laser light, and an LM386 audio amplifier to generate the audio signal sent to a pair of headphone. The need to be well-aligned which is easy enough using a pair of tripods. Check out the demo after the break.

Looking for something to do with the leftover laser diodes from this project? Try making yourself a laser microscope.

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1 Watt laser engraver

This laser engraver was built using printer parts, a CD-ROM carriage, and some homebrew electronic boards. The laser diode is a 1-Watt model similar to what we saw used as a weak laser cutter back in August. When the width of the material changes the focus of the laser is affected so the diode was mounted on a CD-ROM carriage (in the Z axis) for easy adjustment. The X and Y axes are made using parts from Epson Stylus 800 and Epson Stylus Color II printers. After the break we’ve embedded a video of the machine engraving some wood using EMC2 software on an Ubuntu box. It also boasts the ability to cut paper and some plastic but it can’t compare in power to a CO2-based unit.

[Read more...]

Building a laser cutter from a weak laser

We covet laser cutters and this diy model with a 1 Watt IR diode may be well within our price range. Most commercially available laser cutters, and some homemade ones, work in the 20-100 Watt ranges, using a CO2 laser. They have more than enough power to cut right through a lot of materials so how can a 1W diode compare? It seems that the weaker laser is still quite powerful right at its focal length, so moving that point along the Z axis will let you burn away a larger depth of material. The test rig seen above uses optical drive components for the three axes and managed to cut a rectangular piece out of the black plastic from a CD case.

This isn’t [Peter's] first try with CNC lasers. He’s the one that’s be working on an open source selective laser sintering platform.

[Thanks Osgeld and Vesanies]

1W blue laser – remarkably easy and dangerous

We’ve been covering Laser Hacks pretty much since the beginning but it’s surprising to see the niche market that has sprouted up around building powerful handheld modules. [Styropyro] filmed the video above as a tutorial on building a 1W blue laser. The “flashlight” that he starts with includes a heat sink intended for a laser diode. It seems there’s a lot of choices when choosing one of these build kits. A one Watt blue laser diode is press fit into the heat sink and wired in place. The body of the device receives a boost converter to get the batteries up to 1A, and once the assembly is complete the burning begins. It lights candles, matches, and pops balloons; the normal laser demo goodies.

So it’s a pretty easy build. But it’s also easy for someone being careless to damage their eyes. As [Styropyro] mentions in his comments, just looking at the dot created by the laser will damage your sight.

DIY Diodes

[H. P. Friedrichs], the creator of the Static Bleeder has created his own diodes. Using household chemicals, a film of cuprous oxide was made on a copper pipe cap. Cuprous oxide has been one of the first known semiconductor substances, has a low forward drop but is an otherwise asymmetrical conductor, odd V-I curves, and some neat photovoltaic action. The apparatus seen above is used to bring a piece of lead (in this case, solder) into contact with the salmon-colored cuprous oxide while electrical connections can be made to the binding posts at the front. What are your thoughts on this device?