LiPo auto-balancing circuit

ScottD tipped us to the LiPo Auto Balancer circuit featured in the Elektor magazine’s June 2010 issue. When using multiple lithium ion/polymer batteries in series an auto-balancing circuit is needed to make sure all the cells charge equally. Due to slight differences in capacity, some cells will reach full charge before others. This effect increases […]

FPGACheap DIY Altera FPGA USB programmer

This is a DIY USB programer for Altera FPGAs. It only uses a PIC uC and a few discrete components to provide a JTAG interface with a FPGA. Somun found it on a Japanese site (machine translation), and with the help of Google Translate he built one for himself. There are two versions available. The […]

Fingertip heart rate monitor

R-B built a heart rate measurement from fingertip circuit. He also provided all the design files, and general theory of it’s operation: This project describes a microcontroller based heart rate measuement system that uses optical sensors to measure the alteration in blood volume at fingertip with each heart beat. The sensor unit consists of an […]

E-book reader for the microtouch

Rossum built an e-book reader for the microtouch. He wanted to use the common e-book format epub. But unfortunately since the format is actually a compressed set of text, html links and images, it was too much for the 8-bit microcontroller to handle. To overcome this he developed a transcoding tool (epubgrider) to decompress the […]

Controllable aquarium moonlight strip

Theatrus build a controllable aquarium moonlight strip. Royal-blue Osram high power surface mount LEDs provide the lighting, and an ATmega88 the control. RS485 port is used for control. All of the design files should be available shortly. Its quite potent (visible with the main 6x80W T5s running). Its easy to mount (a handful of command strips […]

Gravitech microSD board in custom case

jbeale made a custom case for Gravitech’s microSD boards: That is a real, custom SLA (stereo-lithography) case that was fabricated for a prototype at work- they had the budget for it. It is like the 3D printed things made by a “reprap” type printer, except with finer resolution (I think the layers are each only […]

Let the sparks fly with flyback transformers

Flyback transformers are used to drive the large odd shaped coils surround the neck of CRTs in TVs and computer monitors. They operate in the 15 to 150 kHz range, and can be used to generate high voltages! Uzzors2k decided to experiment with generating voltages high enough to produce arcs, driving the the transformers with […]

Downloadable source for hackerspace passports

Downloadable Source for Hackerspace Passports: You mentioned the Hackerspace Passports Mitch and I designed and I wanted to give you a followup. We’ve released all of the source files used to construct it, including patterns, stamp designs, psd’s, the InDesign layout files, and full resolution illustrations. We’re hoping that people will customize, remix, and develop […]

Video: DSP/SDR basics

Here’s Jeri Ellsworth’s latest video, explaining the basics of DSP and SDR for beginners, and how to build a digital direct conversion receiver (SDR) using sampling detectors and FPGA DSP processing. (If you want to skip the silly cat portion of the video, start at 1:25.) The links referred to in the video are below: […]

Radio Shack announces “The Great Create”

Radio Shack continues to pursue the DIY market: Welcome to The Great Create. We want to know what great creations you’ve come up with using RadioShack parts. Our goal is to gather the coolest projects from our most creative customers and share them here. So, show us what you’ve got and submit your project now. […]

Backcountry logger prototype

Big Mess o’ Wires’ backcountry logger prototype: The Backcountry Logger is a portable microcontroller-driven device that collects temperature, air pressure, and altitude data, and shows graphs on a built-in screen. It’s intended for hikers, climbers, skiers, and other outdoorsy folks who want to geek out with environmenal data about their activities.