I like the idea of repurposing electronics. Occasionally I find something interesting and cheap that begs to be used in a new and interesting way. For example, from time to time the retailer Target releases gift cards with various electronic bits inside. These cards are effectively free since you can use the gift card’s value for your next purchase and then keep the card. Mine was a Speed Racer promotional gift card that was available some time ago. The card housed a 64MB (writable) USB flash disk pre-loaded with Speed Racer content. The card itself is long gone and I unfortunately do not have any pictures of it prior to dismemberment (others have posted pictures of the card though.) Inside the card is a small circuit board and a flexible wired USB connector. This arrangement provides for maximum flexibility for turning just about anything into a small (64MB) but functional USB disk. On the board is an unlabeled surface-mount flash chip, a 12MHz crystal, an LED, and a Chipsbank CBM2090 USB 2.0 flash disk controller (datasheet, pdf). One interesting feature of the controller is the ability to emulate a USB CD-ROM, which can be used for various purposes, nefarious or otherwise. The tool to configure this mode doesn’t seem to be readily available from the Chipsbank website, but a Google search for “CBM2090 umptool” turns up some information about it. The datasheet provides some additional ideas, the CBM2090 claims to integrate a 5v to 3.3v LDO regulator (the datasheet seemed vague on maximum current) and possibly a 1.8V regulator as well. This might be useful for powering a reasonable small circuit. Also tantalizing are the mention of a pair of TXD and RXD serial port pins, and a 32-bit CISC embedded processor. However, the datasheet doesn’t really provide much to go on there. Using the LED for output or control may be another interesting possibility, using commands to eject and mount the drive turned it into a $0.00 USB-controlled blinkenlight. (The LED is on when mounted and blinks rapidly when ejected.)
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