Many of us here in the office (myself included) can’t tell the difference, but the audiophiles out there who want the best sound from their resistors should check out [Troel's] write-up for making your own non-inductive graphite resistors. Graphite resistors have the traits for being non-inductive, have a negative temperature coefficient, and supposedly sound better. We liked the detail of his tutorial and how he gives many examples for making your own graphite resistor.
[Thanks Maxime]

[ Read the rest of the story in the original article... ]

[Viacheslav] built a keypad that uses human capacitance to detect key presses. Unlike normal keys which close a physical connection, his project detects touch through the PCB substrate. He uses the ADC capabilities of an AVR ATmega8 to measure a change in capacitor charges for each sensor in the keypad.
He’s posted the schematic, Eagle files, and source code with his writeup. He also points to a document on the theory behind this: QMatrix Technology White Paper (PDF). We’re impressed at how simple the circuit is: a microcontroller, capacitors, resistors, and a homemade PCB.

[ Read the rest of the story in the original article... ]

[Alex] continues to delight us with his projects. His third-generation tiny Braitenberg vehicle, a light seeking robot, is a big improvement over its predecessor, the mini Braitenberg vehicle. He’s moved from an Arduino based design to using the AVR ATtiny25v, replaced the breadboard with a PCB, and reduced the parts count. We think it was a great idea to use shrink tubing to shield the back of the photo-resistors from ambient light. Don’t miss the video of these little guys chasing a flashlight beam after the break.

[ Read the rest of the story in the original article... ]

Inspired by the multitudes of other automated window blind projects, [John] decided to build his own simpler design. Knowing his Arduino was massive overkill (yes, we hear you all cheering) he picked up a picaxe 08m starter kit.  Looking at his very simple circuit, you’ll notice there are no resistors or capacitors.  He designed it to take commands from his PC via IR. The final product is fairly well hidden, and should his girlfriend ever be upgraded to wife, we assume he’ll hide it better. Good job [John]. We’re no strangers to automated blinds, we’ve seen them a few…

[ Read the rest of the story in the original article... ]

A little over a year ago [Ian Lesnet] joined our hacking team and began cranking out some of the best original how-tos Hack a Day has ever offered. You may remember our popular web server on a business card from last fall and we’re sure everyone is familiar with the Bus Pirate (yes, they’re still on schedule).
It’s a year later and he’s found himself with less time to contribute. [Ian] is stepping down from blogging at Hack a Day, but you’ll find him right where he started: in the comments. You can also reach him directly on whereisian.com.…

[ Read the rest of the story in the original article... ]

For months we’ve used our Bus Pirate universal serial interface tool to demonstrate electronics parts, so it’s only appropriate that the Bus Pirate get it’s own parts post. We recently had a Bus Pirate preorder, and today we received the pre-production Bus Pirate prototype from Seeed Studio. This prototype was mailed just a few days before preorder 1 started to ship, so those packages should start arriving any day.
Follow along as we unbox the prototype Bus Pirate, and connect it to a debugger to determine the PIC24FJ64GA002-I/SO revision that shipped with this board. Use this post to share…

[ Read the rest of the story in the original article... ]

Microchip’s 25AA/25LC EEPROMs are data storage chips with a simple 3-wire interface. The 25AA/LC is an SPI version of the common 24AA/LC I2C EEPROM.  It comes in capacities of 128bytes to 128kilobytes. We looked at the smallest, the 128byte 25AA010A.
There are Bus Pirate demonstrations for most types of serial EEPROMs. Check out our previous 1-wire (DS2431) and I2C (24LC1025) EEPROM posts.
Continue below to see our test circuit and a demonstration of the 25AA010 EEPROM. We used the Bus Pirate to play with this chip from our PC.  For a limited time you can get your own Bus…

[ Read the rest of the story in the original article... ]

Macetech’s ShiftBrite is a high-power RGB LED coupled with an Allegro A6281 backpack. The A6281 uses three 10bit pulse-width modulators to mix millions of colors using the red, green, and blue elements in the RGB LED. Multiple modules can be chained together for bigger projects, like the ShiftBrite table.
Below the break we demonstrate a ShiftBrite module using the Bus Pirate. For a limited time you can get your own Bus Pirate, fully assembled and shipped worldwide, for only $30.

ShiftBrite RGB LED module (Macetech, $4.99). ShiftBrite datasheet and example code, Allegro A6281 datasheet (PDF).
The ShiftBrite module is…

[ Read the rest of the story in the original article... ]