Twisted pair Ethernet (10 and 100 Mbit/s) uses two pairs of wires. 10BASE-T Ethernet was designed to be be used on CAT3 quality wiring. 100BASE-TX was designed to be used with CAT5 wiring or better. Since the early 2000s most new structured cable installations are built with Category 5e or Category 6 cable. There are →
Bartenders beware: A robotic drink-dispensing rig is aiming to steal your customers while pouring cocktail creations at the push of a touchscreen button. This Open Source Robot Bartender Pours the Perfect Mix article tells about bartender robot that the creators call Bartendro: Operated through an iPad interface, this device holds up to 15 bottles of →
A standard hobby RC servo motor is designed to rotate through only 180 degrees. They are most often used in RC applications (like steering). The servo motor controlling is done with servo control pulses (1-2 ms pulse at around 50 Hz rate). More details on the control signals can be found at Servo protocol web →
Need to monitor Linux server performance? Try these built-in commands and a few add-on tools mentioned in 20 Linux System Monitoring Tools Every SysAdmin Should Know article. Most Linux distributions are equipped with tons of monitoring. →
I had been getting some intermittent noise from my Panasonic PT-AE900E video projector after some years of usage. It sounded like a dry bearing on a fan, but it turned out that it was iris that caused the problem. I decided to take a more look at this problems when I had time to change →
EDN magazine reported just few days ago that National Robotics Week has started. There are many robotics events arranged around USA. EDN magazine page from last Friday has a list of links to interesting articles on robotics. There are for example articles on Roomba sensors for hackers and building a power supply for your robot. →
I just accidentally found my way to Super cool video hack: DIY Olympics virtual lane markers page that looked interesting. It says that a student, Xiaoyang Kao, recently figured out how to make his own Olympics-style lane markers. The virtual lane graphics for swimming with css3 page tells how this video effect was done. Instead →
I wrote few years ago blog article Unshielded RCA cable is bad design. I just received yesterday a comment on it: “It’s not always that simple. There are equipment combinations which REQUIRE twisted pair RCA. Here’s explanation: http://www.youtube.com/watch?v=QOagVDZLQnA” So I watched this Truth about RCA signal cables video mentioned on this comment: The video was →
A suitable tool to safely discharge capacitors is needed when you want to work with circuits that have dangerous voltages inside them. Typical examples of such devices mains powered switch mode power supplies (you need to safely discharge main capacitor) and different cameras (the flash unit has a large capacitor charged to 400-500V voltage). Those →
Free and Open—and Their Opposites article gives a a linguistic look at some tenets of Linux. I found it interesting reading because I have written articles to magazines on open source software to magazines and I have needed to think about the right words to use for writing. Here are some information picked from that →