C64 USB Keyboard

July 6, 2009 by Steve Watkins 10 Comments

breadboard

[Maarten] told us about a C64 USB keyboard that was modified to be used as a standard input device. An interesting aspect of the project is the use of V-USB (formerly known as AVR-USB). V-USB is a software only approach to slow speed USB HID. In essence this is a two fold mod, The C64 keyboard is patched to a PC, and an off the shelf AVR is software-hacked to bit bang the USB communications. The author notes an initial problem with multiple key presses that was later corrected in the application. For the other side of the spectrum, we had covered the C64 twittering client, and a commodore 64 laptop.

Parts: Ferrite Beads

July 6, 2009 by Ian 34 Comments

ferrite-bead.ii

Ferrite beads (L1 in the photo) filter high frequency power supply noise by converting it into a tiny amount of heat. Power supply noise can cause various problems for many parts, especially in analog audio and display circuits.

Ferrite beads are simple, but choosing one can be confusing because they’re not commonly used by hobbyists. Most designs will still work if you omit the ferrite bead(s), but beads are so cheap there’s no reason to sacrifice the added reliability they provide. We describe how we pick ferrite beads for our projects after the break.

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World Smallest TV-B-Gone

July 4, 2009 by Zach Banks 41 Comments

uTVBG

The TV-B-Gone has proven to be a dangerous and versatile gadget. At Interactive Matter, they created an even smaller version with more sneaking potential. Called the µTVBG, it packs an entire TV-B-Gone in a 1.4 x 2.5 cm footprint and even has room for a programming header. He found some high-powered surface-mount IR LEDs that would match the original TV-B-Gone’s power. To drive the board, they used a CR1220 button battery on the bottom of the board. The whole thing is smaller than your thumb and should be easier to hide next time you wreak havoc.

Capacitive Discharge Cutting

July 4, 2009 by Steve Watkins 25 Comments

capacitive discharge cutting

Capacitive discharge cutting provides more control than linear transformer versions. A very large capacitor is charged to a precise voltage and then discharged through the material to produce a controlled cut. The same device can also be used for spot and tab welding. A video of copper roof flashing being cut is embedded below. An example of a linear transformer can be found in our our How-to: build your own spot welder.

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Lego Modded Antenna Tuner

July 3, 2009 by Steve Watkins 15 Comments

legomoddedtunner

This antenna tuner is controlled remotely using geared motors and legos. The tuner needed to be closer to the antenna for performance reasons. This created a problem; most of the radio gear is inside while the tuner is outside. The gear motors and Legos combine to form a closed loop servo, operating two air core caps and an inductor switch. A control box placed near the radio is hard wired to the modded tuner outside. We would like to see something like this under gesture control using the Wii MotionPlus + Arduino.

SparkFun Open-sources Latest Kits

July 2, 2009 by Zach Banks 8 Comments

09205-5

SparkFun has started to release some of their kits as open-source hardware. Projects such as ClockIt, a simple alarm clock, have their schematics, board designs, and source code released under the CC-by-sa license. Although most of their widgets and projects already had example code and schematics available, they are now using an open-source license. They are joining adafruit and EMSL and others in pushing OSH, but it is interesting to see an established company turn to this. Normally, startups do this to encourage early adoption.

[via adafruit]

Poor Man’s Thermographic Camera

July 1, 2009 by Steve Watkins 24 Comments

thermographic camera

Using an IR thermometer, there are two ways to go about building a thermographic camera. The first uses a pan and tilt head. Scan lines are emulated, as a computer controls panning from left to right, taking a temperature sample from each step. Vertical resolution is accomplished by tilting. Another method uses a web cam attached to the thermometer. The thermometer’s laser pointer is captured with temperature annotations, as the computer records the field of view. We think the best outcome can be found with a combination of both methods. The video embedded below demonstrates the results. This would be a good addition to the Autonomous paintball sentry.

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