brainwagon

I was tinkering with a small electronics project (article and video to come) and needed a sound output. Digging around in my junkbox, I found one of these piezo speakers, and decided to use it, driving it with a square wave from my Arduino: Piezo Element 1500-3000Hz – RadioShack.com My initial test was supposed to […]

I share an interest in old computing technology with several of my friends and readers. An interesting sub-topic within this vast area is the world of computers based upon relays. In the last couple of days, I found cool links to two different relay based computing projects, so I thought I’d pass them along. First […]

This is just a plug for a cute little pair of gadgets that I got the other day.. If you are like me and use solderless breadboards to experiment with stuff on the Arduino, you end up with the Arduino and the breadboard connected by a hodge podge of wires, and if you accidently tug […]

My G0UPL QRSS beacon is working pretty well, but is only putting out about 40mw of power, when it probably should be putting out 100mw. I was pondering oscillators in general, and (as I do often) surf for information and inspiration. I found both on Steve “Melt Solder” Weber’s website, in the form of a […]

While listening to the Amateur Radio Newsline podcast this week, I was interested to hear that a group of hams from Ireland had launched a balloon which transmitted digital pictures back from the balloon while it was at altitude, using a version of dl-fldigi. While I was familiar with fldigi, I hadn’t heard of this […]

A couple of years ago, I was big into QRSS and wrote some software to do unattended captures of the portion of the 30M band where people were operating beacons. It was through this rather unconventional means that I first discovered Alan, VK2ZAY, as his callsign scrolled across in DFCW. If you look at this […]

Well, it’s done! Here’s my ATtiny13 controlled Christmas LED hat. It consists of an 8 pin, ATtiny13 microcontroller, a pair of 2N3904 transistors and some 1K resistors, a 7805 voltage regulator with two filter caps, and a switch, all mounted on a Radio Shack perfboard inside an Altoids tin. I’m rather pleased with the way […]

While waiting for my bread to rise the other day, I moved my breadboard ATtiny13 circuit that blinked two leds to a small Radio Shack perfboard, added a couple of switching transistors (2N3904s) to power the LEDs, and built a small 7805 regulator (which doesn’t yet have any filter caps, I’ll get to that). But, […]

I needed to know the pinouts for various AVR chips and the 6 pin ICSP cable they used. I found this cool little one page sheet that had that, and more. Saved for future reference: Microcontroller cheat sheet.

Today, Carmen decided that she wanted to give Arduino programming a try. She’s an experienced programmer, but had never tried any of this small embedded stuff, and knows relatively little about electronics, but with a little direction from me, she got the Arduino development environment installed, and we did a bit of playing around. I […]

This morning I woke up around 5:30AM to catch the lunar eclipse. It was pretty nice: totality began around 6:05AM and the moon became incredibly dark and red. But 30 minute later, it had progressed low enough that it entered the offshore clouds that signaled the arrival of the morning fog. So, I came back, […]

More important help for the budding young electronics designer: https://twitter.com/#!/EMSL/status/144546376624250880 Note: this also works in computer graphics quite well. Just specify a negative intensity for the light value.

I didn’t have a lot of time to do anything significant tonight, but I wanted to test a few things about this strand of Christmas lights using a multimeter and some simple math. Recap: there are two strands of LEDs, each wired in parallel. One strand consists of 4 red and 4 yellow LEDS. The […]

I was in a hurry yesterday, and didn’t draw the LED connections in my schematic for the $.99 Christmas lights properly. Mike pointed it out to me on twitter, so I thought I’d post a corrected version of the schematic. I’ve also updated the schematic in the original post, so no one will be led […]

I was over at the CVS repository today, and saw that they had some small strings of fifteen LED Christmas lights on sale for a paltry $.99 (if you used your CVS discount card). That was simply too much to resist, so I got a couple of strings, and thought that I would use them […]