Using an AVR as an RFID tag

Experiments in RFID, continued… Last time, I posted an ultra-simple “from scratch” RFID reader, which uses no application-specific components: just a Propeller microcontroller and a few passive components. This time, I tried the opposite: building an RFID tag using no application-specific parts. Well, my solution is full of dirty tricks, but the results aren’t half bad. I used an Atmel AVR microcontroller (the ATtiny85) and... Read More

Simplest RFID reader?

That’s a Propeller microcontroller board with a few resistors and capacitors on it. Just add a coil of wire, and you have an RFID reader. Here’s a picture of it scanning my corporate ID badge, and displaying the badge’s 512 bits of content on a portable TV screen: If you’re into that sort of thing, I wrote a forum post with technical details and pretty oscilloscope screenshots. Update: The forum link went dead for a while... Read More

Propeller chip + SPDIF = ???

So, kind of on a random whim, I decided to build a software SPDIF encoder for the Propeller chip. It was an interesting challenge, and the results are pretty cool, but now I have no idea what do do with it. Not an uncommon problem for me, I guess… Maybe I’ll give my Propeller board an Ethernet port and build a Squeezebox-on-a-chip. Update: Ok, so maybe that’s not such a crazy idea.. (or is it?) Anyway, I just found this, and I had... Read More

Hard disk laser scanner at ILDA 4K

I should have blogged about this long ago, as I’ve been working on it off and on for about three months now, but today I reached an arbitrary milestone that compels me to post I’m still actively working on this project, so I’ll try to make updates occasionally, and if I end up putting together an actual project web page I’ll link it from here. My latest tinkery hardware and embedded systems project is a homebrew laser scanner.... Read More

R/C helicopter lights, Revision A.5

Atmel is going to personally revoke my electrical engineering license if they ever find out what’s in that yellow heat-shrink blob, but I now have a shiny new 5 gram version of my helicopter light kit =D This version has all the same remote-control dimming and strobe capabilities of the heavier Revision A. The only practical drawback is that it isn’t quite as bright.  Read More

Hardware sketch: R/C helicopter light kit

As great as it is to finish a professional-looking hardware project with optimum component choices and full design documentation, I love the feeling of sketching in hardware (or as I’ve called it in the past, improvisational electrical engineering). Despite all the faults and rough edges in today’s development tools, we do live in a world now where it’s easy turn an idea into a working prototype with very little time and money. Flying... Read More

Playstation controller extender

The little hardware project I started almost 2 months ago is finally done. Completely finished. Bug free! Well, almost. It is, however, in a fully assembled state with firmware that is actually pretty usable. The Unicone2 is the result of my mini-quest to extend Playstation 2 controllers over long lengths of cat5 cable. A while back I did something similar, extending Game Cube and N64 controllers over ethernet. That was the original Universal Controller... Read More

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