brainwagon

Thanks to Bill at the SolderSmoke blog for posting a link to Dave Richards’ construction project. He made a slick version of the Wheatstone Bridge Receiver, a regenerative variant created by N1BYT and published in More QRP Power. I’ve looked at this receiver before, and found the design to be pretty interesting, but Dave goes […]

I was pondering my laser transmitter the other day, and began to think of how I might transmit digital information from the Arduino to the remote receiver. Since I am old, I remember the old days where programs used to be stored on an obsolete audio storage medium called cassette tape. Indeed, the first storage […]

Glancing to the side bar, it appears that today in 2002 was the first post on my blog. This should be post number 3,690. I’ve had 2,286 comments. I’ve used 110 category tags. Over the 12 months, Akismet has removed 193,915 spam comments, and there have been 798 pieces of “ham”. The peak month for […]

The other day, I showed how the Arduino could be used to generate PWM audio and send it over a very short distance using an LED. In my ever increasing pile of parts, I had some small 5mw red laser diode modules. These modules are supposed to be driven by direct connection to three 1.5 […]

This morning I realized that somehow I had failed to listen to the latest SolderSmoke episode (#135), so during my somewhat longer than usual commute (traffic) I set it going and had a listen. And wow, some really great stuff, especially the report by Bob Crane, W8SX on the Four Days in May (FDIM) QRP […]

Back on July 8th, I wrote a brief post about mentoring. Hopefully, some of you read it. In case you didn’t, I made the completely unsupported claim that mentors don’t normally create interest, they merely nurture the interests that are already there. They also serve to help remove the obstacles that frustrate the enthusiasm of […]

I’m still interested in doing light based communication, but I haven’t made a lot of progress. I did build an LTSpice model of the circuit I used yesterday, but other than verifying that it probably would work as built (which it did) I didn’t feel like I had enough brain cells working to optimize the […]

Okay, so last night, after just testing one of the laser modules I had, I decided to try to make a transmitter to send audio over laser light to my “solar cell + Radio Shack amplified speaker” receiver that I was experimenting with earlier. I suppose I could have used my linear current LED modulator, […]

A while ago, I got some laser diodes from from dealextreme.com. They were dirt cheap, but I haven’t had any chance to hook them up. I didn’t have a datasheet for them either, so wasn’t sure exactly what I should do to current limit them. So, I hooked it in series with a 150 ohm […]

An anonymous commenter suggested that I look at logisim, a circuit simulator written in Java. It has many nice features. For instance, you can specify a combinatorial circuit either as a truth table or as equations, and it will convert to the other representation (in minimized forms) and will also build a circuit to implement […]

I was reading that Stanford has begun teaching their introductory computer science course CS101 with Javascript. Despite a lot of the propaganda surrounding the web and a pretty good book on the good parts of Javascript, I can help but think that Javascript has some really tragic flaws. Dijkstra famously referred to PL/1 as “the […]

I apologize. My blog has been remarkably unsociable. Whenever I post to it, I’d like it to also post a short notice to facebook and to twitter. But recently some hiccup happened, and two posts would end up on twitter, and an annoying three would appear on facebook. I think I’ve got that sorted out. […]

Continuing my obsession with reading up on homebrew CPU projects, I found this incredible blog. Instead of just presenting the completed design, Dawid has presented intermediate posts about his project in progress, detailing some of the choices and techniques he had to make along the way. As is true of most projects like this, it’s […]

This morning, I was a bit late coming into work. I decided to sit until 8:26AM Pacific to see if Atlantis would be launched on the final mission of the Space Shuttle program. Low cumulus clouds threatened, but in the end the shuttle rose on its pillar of fire for the last time, and in […]

It’s Friday, and Fridays are good days for thinking. It’s unclear that it is a good day to write about what you’ve been thinking, but here goes anyway. I’m involved in a couple of different communities (hacking and amateur radio) which might be characterized as “ageing”. As a young adult, I was influenced by Steven […]