Pontus Frönder has put together a really simple USB interface for any LCD that uses the HD44780 controller. He used a USB chip from FTDI that creates a virtual COM port on the host computer. This is connected to an Atmel ATtiny2313 which controls the LCD. The AVR has two PWM outputs that are used to control the backlight and contrast. If the current draw of the backlight is low enough it can be driven directly from the USB and since it looks like a standard serial display you can talk to it using programs like LCD Smartie.

Continue reading “USB Interface For Parallel LCDs” →

We’ve had fun with the sensors in optical mice before, but [Mac Cody] wrote in to tell us about his legitimate application of the technology. First, he disassembled the mouse and bypassed the on-board controller. He then wired the clock and data lines to a Harris RTXEB single board computer. It’s based around a Harris RTX2001A microcontroller which he programmed in Forth to talk to the Agilent optical mouse sensor. Documented code is provided in case you want to implement it in a different language. His future plans for the system are to roll it into some robot projects for dead reckoning navigation.

Continue reading “Robotic Motion Sensing Using An Optical Mouse” →

[Leechar] liked the compactness of notebook keyboards and wanted one for his desktop. A friend provided a 486 notebook keyboard and Leechar found an old AT keyboard controller in a junk box. Instead of taking the time to decode the key matrix and make sure that every key was generating the proper scancode he just wired it so that each key generated a unique code. Then using KeyTweak he was able to build a registry key for the correct mapping. Still having fun abusing input devices he decided to marry his Toshiba laptop track ball with the guts of a Microsoft mouse by soldering directly to the photosensor connections.

UPDATE: It looks like we “H-bombed” the 5gigs server within 4 minutes of this being posted. Grynx has a mirror.

UPDATE: Leechar has gotten better hosting, links should be fine now.

Continue reading “Laptop Keyboard Conversion” →

Continuing our trend of peripherals modified to perform functions that aren’t actually useful: here’s how to play music on your scanner. The HP ScanJet 3c/4c have a variable speed scan head that is driven by a stepper motor. The Play Tune command can be used to move the head at different frequencies. Here’s a video of a scanner playing F?Elise. The site we’re linking to has the source code to do this, but newer HP scanners may have hardware activation built-in, according to these two Easter eggs.

Continue reading “Scanner Music” →

“Tempest for Eliza” is a program written by Erik Thiele to demonstrate the RF transmission properties of CRT monitors. The program is capable of transmitting sound over AM frequencies just by the unique way it drives the monitor. The electromagnetic emissions of CRTs can be a security problem as demonstrated by Van Eck phreaking, watching someone’s screen just by collecting RF transmissions. In the late ’90s Ross Anderson developed software to help reduce the RF transmissions of monitors. These specialized fonts combined with shielding can greatly reduce the risk of attack and is something the NSA has been researching for many years.

[thanks gsham]

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As an emulator enthusiast Oscar was frustrated by the button placement on his Pocket PC. He decided to adapt an NES controller to the PDA. The iPAQ had four buttons plus a D-pad like the controller so he just needed to find a way to translate between the two. The answer came from a Belkin IR keyboard. In addition to the regular QWERTY keys it had the hardware buttons too. He stripped out the necessary board from the keyboard and connected the NES buttons. He left the battery and an IR extension outside of the case because the signal was too weak from a distance. I wonder if it would be possible to use something like [leadingzero]’s NES remote and just translate the button presses since the signal would be stronger. I know it would work with LIRC in Linux, but I’m not sure if there is something similar for Pocket PC.

Continue reading “NES Controller For Pocket PC” →