301 Moved Permanently

Posted March 28, 2012 by Chris

“Pictured to the left is the front-end, first mixer and IF amplifier of an experimental GPS receiver. The leftmost SMA is connected to a commercial antenna with integral LNA and SAW filter. A synthesized first local oscillator drives the bottom SMA. Pin headers to the right are power input and IF output. The latter is connected to a Xilinx FPGA which not only performs DSP, but also hosts a fractional-N synthesizer.”

Posted March 27, 2012 by Chris

“In this tutorial, I’m going to show how to interface a Dekatron tube to a Parallax Propeller microcontroller. This is similar technique to what I used in the Packetron-9000 project, although in that project I used mosfets. MPSA42 transistors are much cheaper and a lot easier to interface.”

Posted March 26, 2012 by Chris

“The robot consists of nine cars connected with eight Futaba servos controlled by a microcontroller. All wheels are passive, the locomotion comes entirely from lateral undulation, which is wave movements in the plane similar to a snake. Continue reading for the story behind the project, how we fared at the RoboCup competition with videos, and for details about the electronic hardware, mechanical construction and software.”

Posted March 25, 2012 by Chris

“The board does not contain any microcontroller. So you can decide whether you want to connect it to a PC or to a microcontroller. I created a small piece of C-code software for Atmel AVR microcontrollers to control and test the signal generator. At the moment it is just possible to enter the desired output frequency and the divider is set automatically. It does not make any use of the second frequency register and the phase registers. In addition i did some experiments in creating a WSPR signal with this setup.”

Posted March 24, 2012 by Chris

“This project was an excuse to learn about Verilog and programmable parts (cpld, fpga). I chose this project because someone asked about it on Usenet, and the generic response was “use a ROM” – but to get a ROM wide enough would have been expensive, and wasteful – most ROMs these days have many inputs and 8 outputs, we want one with few inputs and many outputs – 8 (or more) in and 21 out. I suggested a $1 CPLD instead (turns out you need a $2 CPLD), then decided to actually make one to see if it would work.”

Posted March 23, 2012 by Chris

“A couple of days ago, I picked a pair of Xbees at Sparkfun. The plan is to build low power sensor platform using PICs, Zigbee radios, and Linux. In this article, I’m sharing my experience in building with Xbees.”

Posted March 22, 2012 by Chris

“The PICKit3 is microchip’s newest official PIC programmer and MPLABX is microchip’s newest IDE and while people argue about how good they are, the new programmer and IDE have never done me wrong. I upgraded away from the old ICD2 clone programmer that I had used for years when I saw that microchip sells their PICKit3 for under $50 and so now I’ll pass on my experience of how to use these tools to you guys!”

Posted March 21, 2012 by Chris

“I first conceived the idea of using Linux (uClinux) as a lasershow controller at University in 1998 while we were playing around with a Motorola 68332 in our final-year microcontroller course. Linux had just been ported to the 68332 and 68328 and by that time, having been using Linux for a few years, I saw the potential for Linux as a lasershow controller. I then purchased a SnapGear eLIA MCF5307 board in 2000 and have since been working on the idea in my spare time.”

Posted March 20, 2012 by Chris

“For our project, we wanted to push the video sampling and processing capabilities of the ATmega644 8-bit microcontroller. Using a high-speed analog-to-digital converter as an input device, we were able to sample a reasonably high-resolution grayscale image from a color camera’s video output. Using this grayscale image, we are able to track objects and recognize shapes that stood out from the background by a customizable threshold.”

Posted March 19, 2012 by Chris

“The company where I work has recently been doing a big push for safety, and last week they passed out small POV fans with sayings like, “Thx 4 Being Safe”, “Being Safe is Cool”, “I’m a Safety Fan”, etc. The fan has clear, flexible plastic blades, and one of the blades has a strip of 7 LEDs in it which are used to display the messages. The fan itself is pretty cool….but I wanted to see if I could make it say something else.”