brainwagon

Ever on the lookout for software defined radio designs, I was pleased to see G0NQE’s simple receiver design this morning. He offers a kit, but also offers the bare PCB board, and puts the schematic and parts list on his website. Very cool. It’s pretty much a textbook Tayloe-style switching detector, which is implemented entirely […]

I’ve been meaning to do a quick post about podcasts that I listen to that are related to ham radio, just in case there are some among you who may not have heard about them, or who may have heard about them but haven’t given them a try. Here’s a list of what I listen […]

Maker Dino Segovis has a website called hackaweek.com where he tries to do a hack a week, streaming his construction via uStream, and then posting youtube video and details on his blog. This week, he decided to build a copy of Alexander Graham Bell’s PhotoPhone in celebration of the 131st anniversary of its unveiling to […]

Radio Shack recently posted this (as yet, not incredibly popular) video asking for feedback on what they could do to support the DIY/Maker community: I’ve thought about it off and on for the last couple of days, and read some other blog posts, and I thought I’d give my take on it. I mostly don’t […]

Today, while scanning around for things that I could watch on Netflix streaming, I found that they had The Adventures of Prince Achmed, which was a movie which I had heard about, but had never seen. Wikipedia claims that it is the oldest surviving full length animated feature film, dating back to 1926. I first […]

Fellow hacker Mike Cowlishaw tweeted me a reminder that he had worked on a design for a spelunker’s headlamp that used Luxeon LEDs, and had excellent high performance. I remember that I listened to a talk about this design, but at the time, I wasn’t saavy enough in electronics to grasp the details, and it […]

I’ve been pretty happy with the performance of my linear current based LED transmitter, but that was just sitting on the bench, driving a 20ma device. As I played with the circuit, I began to realize that if I scaled the circuit up to a 1W LED, its deficiencies in terms of efficiency would become […]

My recent experiments with light based communication left me thinking about simple circuits for driving LEDs. I’ve got three big LEDs (1W) on order from deal extreme, so I was looking for circuits to drive these larger LEDs. This Instructable has some good ideas. I’ll probably breadboard some of these soon. High Power LED Driver […]

At various times, I’ve been interested in writing operating systems. I haven’t done much thinking about this recently, but it is a topic of interest. I hadn’t seen this project before: a small 64 bit kernel written in assembly. I have no idea whether it’s interesting, but I thought I’d bookmark it for future investigation. […]

Huzzah! I’ve been wanting to get a Funcube Dongle Pro for some time, but they have been in short supply. Today, a fresh batch went on order, and this time: success!! The Funcube Dongle Pro is a cool little software defined radio that plugs a USB port, and receives from 64Mhz to 1700Mhz. I am […]

A few days ago, I posted a query to twitter regarding voltage drop in LEDs: I didn’t receive a lot of truly helpful replies: a few people reinforced the general dogma that indeed LEDs were diodes, and since they were diodes, they should have relatively constant voltage drop despite current across them. But that’s not […]

Today, I had to do some yardwork, so I dusted off the weed whacker, and climbed the back of the hill to chop down some high grass. At the end of an hour, I was about 40% done (I’ll do the rest next weekend) but sneezing and coughing from the liberated pollen and dust. So, […]

While surfing for more LED information, I found this rather nifty little circuit on Electronic Design’s website. It’s a little Joule Thief-like circuit, but with enhanced efficiency (~80%) and it can drive white LEDs with rather large forward voltage drops. Archived for later…. Single Alkaline Battery Drives White LED.

When I was still in grade school, I (and this will be a shock to my readers) spent a lot of time in libraries. Our library used to have a free bin, where they would toss things that they no longer wanted in their collection. One day, I came by and found a pile of […]

IRC and Minecraft buddies Atdiy and whisk0r have been doing some cool videos on making cigar box guitars, some kind of neural network stuff, and more recently: some introductory electronics videos. After winding inductors and making their own capacitors in previous episodes, they get around to making their own foxhole radio just using a blued […]