Electronics Design

Resistors

The resistor is the most common and well-known of the passive electrical components. There are many uses for resistors: they are used to drop voltage, limit current, attenuate signals, act as heaters, act as fuses, furnish electrical loads, and divide voltages. Resistor 101 tutorial provides an in-depth guide to the types of fixed resistors, their

Open Hardware Journal

I just saw Slashdot posting mentioning Open Hardware Journal. Open Hardware Journal is a new open technical journal on designs for physical or electronic objects that are shared as if they were Open Source software. It’s an open journal under a Creative Commons license. You can download the magazine in pdf file format and redistribute

Bitbang Ethernet

Implementation UDP into microcontroller Igor Atmel-UDP device: UDP/IP infrared remote control web page shows implementation UDP/IP on firmware level (similar as emulation of RS232 interface or USB interface). What makes it really cool is that the ethernet is bitbanged using nothing but the bare pins of an ATMEGA168. The downside is that this Ethernet implementation

Agile hardware development?

Software developers have largely accepted the merits of agile development and commonly debate the value of one agile practice against another. Agile software development is a creative process that does not need all details to be defines in advance. Agile software development is a group of software development methodologies based on iterative and incremental development,

AC current levels

AC current levels 0.25mA  Maximum Leakage Current for Class II equipment in IEC 950 (Information Technology Equipment, I.T.E.) (no protective earth ground in the equipment, double insulation or reinforced insulation) 0.5mA Earth Leakage Current limit in IEC 601-1 (Medical Equipment) (this is general value, here are also other leakage current requirements in IEC 601-1) 0.5mA

Measure with soundcard

Unless you add a measurement instrument to your computer, you have only the sound card as an analog I/O port. You can use the sound card to digitize ac analog voltages but only within a limited range. You can, however, add some signal processing and measure a wider variety of signals, even those that produce

Counterfeit parts

Watch out for well-made (counterfeit) chips. Counterfeit parts are big headache. Saelae tells that they noticed first that many more boards than normal were failing the functional test. The USB chip was running hot. It turned out that every last part was an old revision corresponding to a different (obsolete) part number – the parts

FPGA-based Ethernet switches

Ethernet switches are the ubiquitous building block of any intelligent network. Ethernet technology is deployed in virtually every organization’s data center. Wide Area Networking (WAN) and Metropolitan Area Networking (MAN) providers need to provide their customers with Ethernet services. Ethernet has also become the de facto networking technology in industrial automation even in mission-critical local