Direct-to-PCB Inkjet Printing

September 2, 2009 by Phil Burgess 33 Comments

inkjet-pcb

Full Spectrum Engineering has offered up a tutorial for their inkjet direct PCB kits that repurpose direct-to-CD capable inkjet printers (such as the Epson R280) to print etch-resistant ink straight onto copper clad board. This is easier and less error prone than some iron-on methods, especially for two-sided boards. Just print (no need to reverse the design), dry on a hot plate or in a toaster oven for a couple minutes, and your board’s ready for etching!

Homebrew methods exist for all of this, but for those who would rather move ahead with their design than spend time scrounging for the required bits, the kits offer a pretty good value. They can also meet you halfway…say if you’re only lacking access to a laser cutter and just want the CD stencil…all of the parts are available individually or as a complete set: the resist ink cartridge, the stainless steel board-holding stencil, and a supply of double-sided copper clad boards precisely sized for the stencil (3.5 by 2.5 inches). The small board size is well within the limits of the freeware Eagle Light Edition software.

Concerned about gunking up your nice inkjet with non-OEM ink? You can dedicate hardware to the job without breaking the bank. Many of the compatible printers are of the “free printer after rebate” bundle variety that can now be found inexpensively on Craigslist or eBay.

USB Gameboy Cart

August 28, 2009 by Zach Banks 20 Comments

gamecart

[Jose Torres] sent in his latest attempt at creating a custom Gameboy game cartridge. We’ve featured his projects before, and he’s come a lot closer over the last 2 years. He’s aiming to create an easy interface for homebrewers that doesn’t require any other special equipment. In this revision, he’s using a PIC and a memory controller to interface between an SD card and the Gameboy. The cart also has USB support for uploading files to the SD card and reprogramming the PIC. Because it’s just USB mass storage, it will work on almost any modern OS. He’s currently testing the device, but hopes to be selling them soon for $40.

Collect And Analyze ECG Data

August 22, 2009 by Zach Banks 14 Comments

ecg

Although we’ve covered DIY ECGs before, [Scott Harden] sent in his version that gives an in-depth explanation of what to do with the collected data. He built a basic battery-powered op-amp-based ECG for under $1. The circuit just amplifies the signal from the chest leads and feeds it into a computer via the microphone port. He then used GoldWave to record, filter, and save the signal. From there, he used python to analyze the heartbeat and calculate his heart rate and further manipulate the data. His previous blog posts go into more detail on how the python code works and why he chose software over hardware filters.

Adafruit Releases New TV-B-Gone Kit

August 17, 2009 by Nick Caiello 54 Comments

Recently, our friends over at Adafruit released a new version of their popular TV-B-Gone kit. Built in cooperation with [Mitch Altman], the inventor of the TV-B-Gone, the new kit sports four high power IR LEDs, two wide beam and two narrow beam. The four LEDs give the new TV-B-Gone increased range, with a maximum distance of over 150ft. One of the most impressive features of the kit is the fact that the new TV-B-Gone is universal and can now work in Europe and Asia in addition to the US. Users are able to select which region they want to use during the build process by soldering a resistor into the board at their region’s corresponding spot as seen in the picture above. The new TV-B-Gone kit is now available in the Adafruit store for $19.95 plus shipping.

Serial Hacking With An ATtiny2313

August 6, 2009 by Steve Watkins 19 Comments

board

[Sprite_tm] automated a portion of serial hacking by sniffing out the baud rate using an ATtiny2313 and FT232 breakout board. The firmware assumes 8 data bits, no parity, and 1 stop bit (8N1). This is pretty much defacto among serial ports so it should work well, though some devices do use different settings. The auto detection routine can sniff rates as low as 110 baud and supports non standard rates. Released under GPLv3, the software is also supplied in hex format. [Sprite_tm] has provided great project in past such as Working with VFDs, Controllable bristlebot, and AVR boost converter. Additional information regarding serial hacking after the break.

Continue reading “Serial Hacking With An ATtiny2313” →

Custom Flex Sensors

July 25, 2009 by Zach Banks 14 Comments

flex

Flex sensors, like the ones used in the Nintendo Power Glove, are generally expensive and hard to find. However, [jiovine] demonstrates that they are easy enough to make from spare parts. He sandwiched a strip of plastic from ESD bags between pieces of copper foil, and wrapped the whole thing in heat shrink tubing. The sensor is able to detect bends in either direction, unlike the original power glove sensors. His version had a nominal resistance of about 20k ohms, but by choosing a different resistive layer you could create sensors that are more or less resistive.

Related: 5-cent tilt sensor

Pet-squirting Waterwall

July 24, 2009 by Zach Banks 8 Comments

waterwall

Sometimes, pets need to be trained to stay away from certain things. Over at sump.org, his cats needed to be kept out of his room. He used their natural fear of water by creating the waterwall, a motion-sensing device that sprays water. The project is incredibly simple and uses very few components. It is based around an IR intrusion detector and a windshield washer pump. Although that worked well enough, he also hooked it up to his computer via the parallel port so that he could take pictures as the cats (or people) are sprayed. Although the project is old, it shows how few components are really needed to achieve this kind of behavior.

Related: Motion detecting cat toy

[thanks todd]