Archive for month: November, 2011

The art of capacitive touch sensing

November 28, 2011 | Arduino, electronics | By: Mark VandeWettering

I didn’t get a lot of electronics hacking done, but I found myself again playing with capacitive sensing. I found this interesting article on the EE Times website: The art of capacitive touch sensing It also pointed me at the following pretty cool Youtube! vid by the folks at Nerdkits: My experimentation thus far has […]

The Sparkfun Serial LCD

November 24, 2011 | Arduino, electronics | By: Mark VandeWettering

I was driving around various Silicon Valley electronics and surplus stores (like HSC and Anchor Electronics) and decided to stop in at Microcenter. I remembered that they supposedly were beginning to stock items from Sparkfun and the Maker Shed. And, indeed they do! I found a Serial LCD module from Sparkfun that I thought might […]

Apologies for slow website this morning…

November 21, 2011 | Announcements | By: Mark VandeWettering

You might be experiencing slow response to my website this morning. I think it is merely the perils of using inexpensive shared hosting, but I’ve filed a support ticket and hope that it will get resolved shortly. I appreciate your attention, and hope you will persevere in reading, even if the site seems a bit […]

Diode temperature sensor update…

November 21, 2011 | Arduino | By: Mark VandeWettering

Lee mentioned that the there was a way to change the analog reference used on the analog inputs to the Atmel AVR to an internally generated 1.1V, which would give me a lot greater resolution (about little over 1mV per step). Indeed, a little quick searching yielded that it was not only true, but dead […]

Using a 1N4148 diode as temperature sensor…

November 21, 2011 | Arduino, electronics | By: Mark VandeWettering

I had an application where I wanted to detect temperature. No big deal, lots of good temperature sensors exist. But of course, I don’t have any of those. Rather than order something from sparkfun, I thought I’d just try to see what I could do with the stuff I had on hand. What I had […]

A cool little computer: FIGnition

November 19, 2011 | electronics, Link of the Day | By: Mark VandeWettering

I keep looking for cool projects where people build small computer and microcontrollers, more or less from scratch. Today, I ran across FIGnition: FIGnition is a £20 educational DIY computer which works like an 8-bit home Micro: outputting to composite video and ready to be interactively programmed from the moment you switch it on. It […]

A Low Power 477Thz beacon

November 17, 2011 | Amateur Radio, electronics | By: Mark VandeWettering

I mentioned that Roger, G3XBM was shifting from the very low frequencies to much higher frequencies. His interest has already uncovered some links that I hadn’t seen before. One very cool thing was his discovery of a local 477Thz beacon (that’s red light) that is aimed roughly in his direction at a distance of around […]

Arduino PPT Solar Charger

November 17, 2011 | electronics | By: Mark VandeWettering

A conversation I had recently got me on the topic of solar energy, and introduced me to something I hadn’t heard of before: maximum power point tracking. The basic idea is solar cells exhibit a complex non-linear relationship between illumination, temperature and resistance. This is usually represented by an curve that (for a given temperature […]

Codec 2 at 1400 bits/s from David Rowe

November 15, 2011 | Amateur Radio | By: Mark VandeWettering

I’ve mentioned Codec 2 a few times in the past, but for those who don’t rememember, David Rowe has been working on a very low bitrate codec optimized for speech applications. This is of interest in amateur radio because we don’t have a suitable speech codec which isn’t patent encumbered (if for instance, DSTAR’s AMBE […]

A nifty partition of 1..16

November 15, 2011 | Math, Puzzles | By: Mark VandeWettering

Courtesy of Phil Harvey’s Puzzle « Programming Praxis, I discovered that the numbers from 1..16 can be partitioned into two 8 element sets, with these nifty identities! 2+3+5+8+9+12+14+15 == 1+4+6+7+10+11+13+16 22+32+52+82+92+122+142+152 == 12+42+62+72+102+112+132+162 23+33+53+83+93+123+143+153 == 13+43+63+73+103+113+133+163 There has to be a good way to use this to make a cool geometric puzzle as well.\ Bonus: […]

ANGST: the Arduino n’ Gameduino Satellite Tracker

November 13, 2011 | Amateur Radio, Amateur Satellite, electronics, My Projects | By: Mark VandeWettering

I’ve stopped hacking on my Arduino/Gameduino satellite tracker for now. Here’s the final video demonstrating it running: I’m currently working on the final schematic which will be posted on this permanent page. The code will be available, for right now, it includes the library that I wrote that does the satellite prediction. I’ll be […]

JeeNode v6 Kit from Modern Device

November 13, 2011 | Arduino, electronics | By: Mark VandeWettering

I’ve been playing a great deal with Arduinos lately, and have acquired a couple of Xbees to experiment with wireless. But Xbees, cool as they are, are kind of expensive for many tasks where a much simple RF link could suffice. Today, I ran across the JeeNode, which is available as a kit from Modern […]

Xv6, a simple Unix-like teaching operating system

November 10, 2011 | Operating Systems | By: Mark VandeWettering

I like operating systems. My first exposure to Unix was a revelation. Unix was a complex operating system that provided useful facilities for programmers, and it wasn’t written in assembler and locked away: it was written in C (the same language that you use to write ordinary programs for Unix) and it was understandable. This […]

VK3YE’s USB port powered 40 metre milliwatt transmitter on air

November 10, 2011 | Amateur Radio | By: Mark VandeWettering

I was looking for beacon circuits, and ran across VK3YE’s USB powered 40m transmitter. Unlike most simple beacon transmitters, this one transmits double sideband, which makes voice transmission possible. I like the basic idea! USB port powered 40 metre milliwatt transmitter on air – YouTube Very cool. He’s also got an awesome awesome YouTube channel, […]

KD1JV on boost and buck converters implemented with an ATtiny13V

November 9, 2011 | Amateur Radio, electronics | By: Mark VandeWettering

Legendary QRP hacker Steve “Melt Solder” Weber has some awesome stuff on his website, particularly if you are interested in homebrew ham radio gear.   (Indeed, it appears he’s about ready to offer his legendary ATS-4 5 band rig kits again, experienced kit builders might want to check it out.)   But what drove me to his […]