Laser Spirograph

February 21, 2013 by 11 Comments

laser-spirograph

Here’s a weekend junk bin project if we’ve ever seen one. [Pat] used a quartet of computer fans to make his laser Spirograph. Deciding to try this simple build for yourself will run you through a lot of basics when it comes to interfacing hardware with a microcontroller. In this case it’s the Arduino Nano.

The Spirograph works by bouncing a laser off of mirrors which are attached to the PC fans. When the fans spin the slight alignment changes cause the laser dot to bob and weave in visually pleasing ways. You can catch twenty minutes of the light show in the clip after the break.

Three of the fans have mirrors attached, the housing of the fourth is used to host the laser diode and make assembly easier. A TC4469 motor driver is used to connect the fans to the Arduino. The light show can be manually controlled by turning the trio of potentiometers which are read using the Arduino’s ADC.

If you manage your way through this build perhaps you’ll move on to a setup that throws laser light all over the room.

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Bit Banging Through A USB Parallel Port Adapter

February 21, 2013 by 25 Comments

If you’ve ever looked into low-level parallel port access you may have learned that it only works with actual parallel port hardware, and not with USB parallel port adapters. But here’s a solution that will change your thinking. It borrows from the way printers communicate to allow USB to parallel port bit banging without a microcontroller (dead link, try Internet Archive).

Sure, adding a microcontroller would make this dead simple. All you need to do is program the chip to emulate the printer’s end of the communications scheme. But that’s not the approach taken here. Instead the USB to RS232 (serial) converter also pictured above is used as a reset signal. The strobe pin on the parallel port drives an inverter which triggers a thyristor connected to the busy pin. Thyristors are bistable switches so this solution alone will never clear the busy pin. That’s where the serial connection comes into play. By alternating the data transmitted from the computer between the bit-bang values sent to LP0 and 0xF0 sent to the serial connector the eight parallel data bits become fully addressable. See the project in action in the clip after the break.

Framing Up Your Electronics Projects

February 21, 2013 by 8 Comments

framing-up-your-projects

[Victor] may be onto something when it comes to project enclosures. He’s using a picture frame to house his electronics projects. This is made especially easy by the variety of sizes you can find at Ikea. Possibly the most important dimension is to have enough frame thickness to sandwich your components between the glass and the back plate of the frame.

The project seen here is a temperature data logger. The frosted diffuser covering everything but the LCD screen and gives you a glimpse of what’s mounted to the back panel. He connected the four different protoboard components, along with a battery pack, to each other use right angle pin headers. They were then strapped to the back plate of the frame by drilling some holes through which a bit of wire was threaded. He even cut a hole to get at the socket for the temperature sensor and to attach the power input. So that he doesn’t need to open the frame to get at the data, the SD card slot is also accessible. His depth adjustment was made by adding standoffs at each corner of the frame, and replacing the metal wedges that hold the back in place.

You don’t need to limit yourself with just one. This UV exposure rig uses three Ikea frames.

Retro Gaming Just In-case

February 21, 2013 by 12 Comments

retro-gaming-just-in-case

You can look and look, but you won’t find a Super Nintendo inside of this retro gaming rig. [Webrow] is giving his vintage hardware a rest, and taking this all-in-one game emulator suitcase wherever he goes.

The machine at the heart of his build is of course a Raspberry Pi. You really can’t beat the ubiquitous board for cost, power, and hardware extensibility. An LCD panel from a broken laptop comes along for the ride having been mounted in the lid. For a long time there was no hope for reusing these panels, but [Webrow] found an adapter board (for nearly the same price as the RPi) which converts the DVI from the Pi to the LVDS needed by the screen. The connections and mounting scheme for the screen were where most of the project work was done. Connecting the controllers simply involved soldering some SNES controller sockets to an RPi breakout connector. We do have to compliment him on the red bezel which hides all of the power cords and other unsightly bits. The case look sturdy and ready to play!

Swiss Army Keys

February 21, 2013 by 56 Comments

swiss-army-keys

This isn’t a hack that shows you how to start a car without the keys. It’s a way to ditch the bulky keyring for a set of fold-out keys. [Colonel Crunch] removed the blades from the pocket knife and replaced them with the two keys for his car (one is ignition and door locks, the other opens the trunk). He didn’t take pictures of the process, but he did link to this unrelated guide on how it’s done.

About one minute into the video after the break we see each step in the build process. First the plastic trim is removed from either side of the knife. The blades are basically riveted on; there’s a pin which holds them in and either side of it has been pressed to that it can no longer move through the holes in the frame. To get around this one side is ground off with a rotary tool, and the pin is then tapped out with a hammer. The removed blade/scissors/tool is used as a template to cut the body of the key down to size and shape.  The pin is then hammered back into place before putting the plastic trim back on.

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Making Eagle Work With Circuits.io

February 21, 2013 by 25 Comments

IO

Ever so slowly, we’re inching towards a world of Internet-based electronic design tools. The state of these tools, including Upverter and other cloud-based solutions, hasn’t been all that great until now; with any new piece of schematic capture and PCB layout software, the libraries will be woefully inadequate in the beginning. This is about to change, because circuits.io is now allowing Eagle libraries to be imported.

As you may well be aware, Eagle is the de facto standard for homebrew and hobbyist schematic capture and board layout software. Even though Eagle isn’t open source and is limited to rather small PCBs with the free version, somehow Eagle has retained its popularity, most likely due to the huge number of component libraries available.

By allowing users and designers to import Eagle libraries, the folks at circuits.io are capitalizing on a huge amount of work done by designers and engineers over the years in creating custom Eagle parts for just about every component imaginable. It’s a great accomplishment for the circuits.io team and a boon for anyone wanting to move their PCB design tools over to the cloud.

Pair Of Musical Hacks Use Sensor Arrays As Keyboards

February 20, 2013 by 2 Comments

sensor-driven-musical-keyboards

This pair of musical keyboard hacks both use light to detect inputs. The pair of tips came in on the same day, which sparks talk of consipiracy theory here at Hackaday. Something in the weather must influence what types of projects people take on because we frequently see trends like this one. Video of both projects is embedded after the jump.

On the left is a light-sensitive keyboard which [Kaziem] is showing off. In this image he’s rolling a marble around on the surface. As it passes over the Cadmium Sulfide sensors (which are arranged in the pattern of white and black keys from a piano keyboard) the instrument plays pitches based on the changing light levels. [Thanks Michael via Make]

To the right is [Lex’s] proximity sensor keyboard. It uses a half-dozen Infrared proximity sensor which pick up reflected light. He calls it a ‘quantised theremin’ and after seeing it in action we understand why. The overclocked Raspberry Pi playing the tones reacts differently based on distance from the keyboard itself, and hand alignment with the different sensors.

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