Not everyone understands how multimeters measure RMS voltage. Doug Criner has put a good explanation. Can there be more than one RMS value of a voltage waveform, but only one of them is true? Apparently so.To use simple Ohm’s law and power calculations for a periodic waveform, we must know its RMS, or root-mean-square value–which […]
Author Archives: SQKYbeaver
A call to arms
Seeed Studio is asking for help creating an open source radiation sensor, to help in the wake of the Japanese Tsunami earthquake. Can open hardware community do something to help in this? Seeed Studio is now sourcing sensors, then assemble quick measurement tools, ship as many/fast as possible to Japan. Since we have no previous […]
Pitch Shifter
Marcus created a pitch shifter using a pic24 and a few other components, he has posted schematic and has a video of it in action. via The Forum
Pi day
Much to the delight of many eccentric math teachers, today is PI day. Probably organized as a way to interest kids in math, many of us may have at some point in our lives have been involved in the celebration of this important number. We would love to hear about your experiences, or how you […]
Repair your own oscilloscope
Hotsolder repaired his malfunctioning Rigol, A bad rotary encoder can make your tools useless in worst cases. Fortunately it is an easy fix, he has created a slide show demonstrating just how easy it is. Via Hack a Day
Operational Amplifier howtos
The operational amplifier is one of the most useful analog ICs available, and one of the most daunting for beginners and experienced engineers. Above is a diagram of an op-amp in a closed loop non inverting configuration. Probably the most used configuration. Lets assume this is an ideal amplifier. R1 is the input and R2 […]
Build a robot without programing
Cubelets is robotic building platform, simply stick the cubes together and what it go, want it to do something different, just move the blocks around. Via Pcworld
A look inside an OBD2 tool
Any car newer than 1995 has a fairly sophisticated computer used to monitor various systems ranging from accelerator pedal position to catalyst efficiency. This is a brief introduction to one example of the hardware used to diagnose automotive systems.
Droid owner beats radar
Sahas Kata had a minor run in with the law, an officer claimed he was speeding, 40 in a 25. fortunately he was running tracking software on his new droid phone. once in court he asked the officer when he was last trained on use of the radar gun, when it was last calibrated, etc. […]
Diy Superprobe
Ben Ryves built his own version of the superprobe. having no need for some of the standard features he has modified the source for additional functionality. there is an excellent video of Ben demonstrating his superprobe after the break.
Automated Life Jacket Detection
Sentient has added software to search for high visibility objects such as life jackets to their Kestrel Maritime target detection software, that will allow UAVs to reduce the time needed to search large areas, and providing rescuers with direct coordinates, increasing survivability for those overboard. Via slashdot
IBM’s Watson beats Jeoprady legends
The IBM Jeopardy challenge is over and a new champion has been crowned! Watson, the size of 12 refrigerators, three day total was $77,174. While Ken Jennings, known for winning 74 consecutive games, finished with a total of $24,000. And Brad Rutter, known for winning over $3,000,000 on the show, finished with $21,600. With the […]
3D printed guitar
Bård S D built a guitar with a 3D printer. but not any guitar, built to his own specifications he wanted to it to be minimalist and functional. many of the parts double like the pick holder and hand rest. There is a video after the break. via Hack a Day
Arm development board giveaway
Brian has finished a development board for the Luminary Micro LM3S3651, and will be giving away 2 of these boards. I want to give two of these away to people in the Dangerous Prototypes community, just tell me what you would do with it. I will pick two out of the first 50 ideas or […]
Pic web development board
Inspired by the business card web server designed by our own Ian, Arthurb created a development system based around the pic 24f and enc28j60. With multiple daughter cards, for touch sense, serial lcd, temperature sensor, keyboard and monitor. this seems to be a versatile system for development. Via Hack a Day Get an assembled Web […]
TI launchpad as morse keyer
echOs built a CW(Morse code) transmitter using a TI launchpad with a minimal amount of components. Only capable of low power transmitting, this would be use full for finding that lost high altitude payload, or fox hunting. Via: Hack a Day
A guide for using IMU devices
Starlino has a great article on using gyroscopes and accelerometers. I’ll try try to cover few basic but important topics in this article: – what does an accelerometer measure – what does a gyroscope (aka gyro) measure – how to convert analog-to-digital (ADC) readings that you get from these sensor to physical units (those would […]
Online circuit simulator
There is a java based circuit simulator at falstad.com, capable of simulating many passive and active components, as well as logic.
Secure usb time stamp
Simon Inns created a secure USB time stamp device. This project implements a USB device which provides a real-time clock for the purpose of time-stamping events in an non-networked embedded computer environment. For embedded applications where a periodic time-stamp is required (such as entry-system logs, configuration audit logs, etc.) it is necessary to have a […]
Hack a Day now has a forum
Hack a day now has a forum. They have Help Me, Brainstorming, events, and Project log categories. Via Hack a day