Here is a project for locking and unlocking with a tilt sensor by tilting it in a defined sequence. It uses an accelerometer module to detect the tilt motion. If the sequence matches with the predefined motion sequence, the lock opens. You can build this lock for a briefcase, ballot box, portable cashbox or even …
UPDATE: code posted below Nike+iPod is a very interesting piece of hardware for all kinds of reasons, not the least of which is that it as actually useful. It works by wirelessly transmitting data from a sensor (that is stored in your shoe) to a receiver that is either externally connected to your iPod or to …
Nike+iPod reverse engineering (protocol too) using pic microcontroller Read More »
Remember the old video game Space Invaders? Some of its sound effects were provided by a chip called the 76477 Complex Sound Generation chip. While the sound effects1 produced by this 1978 chip seem primitive today, it was used in many video games, pinball games. But what’s inside this chip and how does it work …
e’re living in a golden age of software, where many useful programs are available – for free! Let’s survey some of what’s out there that just might interest an engineering crowd like the EDN community. I can’t offer personal opinions on most of these packages, but I expect to hear back from you after you’ve …
A computer’s arithmetic-logic unit (ALU) is the heart of the processor, performing arithmetic and logic operations on data. If you’ve studied digital logic, you’ve probably learned how to combine simple binary adder circuits to build an ALU. However, the 8008’s ALU uses clever logic circuits that can perform multiple operations efficiently. And unlike most 1970’s …
Reverse-engineering the ALU of 8008 microprocessor Read More »
What’s inside a TTL chip? To find out, I opened up a 74181 ALU chip, took high-resolution die photos, and reverse-engineered the chip.1 Inside I found several types of gates, implemented with interesting circuitry and unusual transistors. The 74181 was a popular chip in the 1970s used to perform calculations in the arithmetic-logic unit (ALU) …
Inside the 74181 ALU chip: die photos and reverse engineering Read More »
A recent eBay fishing expedition yielded an interesting little part for the very reasonable sum of about five pounds. It’s a voltage regulator module from a Dell PowerEdge 6650 Xeon server. I originally bought this because I had the idea of salvaging parts from it to use in another project. These are high quality modules …
Reverse engineering a server CPU voltage regulator module Read More »
