Friday, November 27, 2009

Card Reader Tinkering

So, I have a habit of collecting electronics that even I can only refer to as "junk." It's even in a big box, labelled "junk." There's around 15kg of it that I just can't bear to leave behind every time I move... Needless to say, much of it consists of equipment pulls and junk I desoldered from old VCRs, microwaves, fridge relays, and such, and these are often sensors or actuators I want to try interfacing. This has turned into a regular hobby and has actually opened up a larger part of the world of electronics for me...

All that garble aside, I had a Mag-tek 21006505-based Track 2 magnetic card stripe reader sitting around, which I had purchased surplus from All Electronics way back in the day. It's a slide-through system that can be mounted on just about anything flat, and was purchased for ~$4USD... These days, they offer a different model for about the same price, but this one requires the card be inserted into a slot and removed quickly... Coincidentally, Hack Miami made a Sanguino interface program for this particular reader, but I didn't know about this until after my tinkering. Also, Sparkfun has a 3-track RS-232 serial reader, even an expensive USB reader/writer, but I can't say I'm "$60 interested" in this field. $4 for Track 2 is just fine with me.

So, why did I bother? Well, besides the thing just gathering dust in the Junk Box, who hasn't, at one point, wondered was was on the magnetic cards in their wallet? I had some hope that more interesting things than just the number on the front would be there, and I wasn't disappointed. I don't plan on using this anywhere else, so I just used the Arduino platform to get a quick prototype "sketch" going, reporting the information back through the Serial Port. Rather than just throw the code at you, however, I'll explain what's being read off Track 2, and what resources I used to figure this out...

Tuesday, November 24, 2009

Modding a PL-2303-based USB to RS-232 Adapter for TTL Serial

So a while back, user "tytower" on the Adafruit Forums needed a USB to Serial adapter to talk to his serial radio receiver, and was asking about connecting the 5V level system directly to a USB to RS-232 adapter.

I tried this for kicks on the receiver line of one to get information from an Arduino Diecimila with the provided example "ASCII Table" sketch. It didn't work. Here's why, and how to hack a PL-2303 based USB to RS-232 adapter for TTL level serial:

Sunday, October 4, 2009

USB Hub + International Palm Charger = International USB Charger

So, I recently got one of those iThingies, and this, along with the following factors, prompted the creation of an international, multi-port USB charger:

Main Screen Turn On!!

Well, this piece of karp was supposed to be named something more like "Pressure Drop," owing back to an old name I wanted to call my Nerf gun modding website way back when (as user "Zero Talent"... Ugh), and lending itself to the idea that I'm utilizing this site as a method to get rid of "braincrack" qua built up mental pressure... But it's probably just going to become overrun with half-baked plans, emo, and excessive ellipses... ... ...

Aside from that, here's a picture of my camera's guts taking a picture of its own shell as I repair it in my hotel room prior to PAX 2009: