Thursday, January 8, 2009

Keyless Entry

I hate keys. I'm striving for a zero-key life. To that end, I've started on this little electronics project to automate the lock of my front door. There will be a discrete set of switches that look for a magical unlock sequence. I have an odd relationship with electronics. On the one hand I feel like I know the theory fairly well and I'm at home once the circuit is digital and connects to the computer. But in between those two is reality. The circuit seemed simple enough to just solder straight to the board. Bad idea. Meanwhile, I made totally rookie mistakes with the ground and managed to literally cross some wires. Also, I purchased a touch sensor IC (QT1103) because the data sheet said that it had an RS-232 out which is a protocol I know well from BBS modem dayz. Turns out there's a newer protcols (Dallas semiconductor's 1W) which is 100% incompatible with RS 232 yet mysteriously still uses the RS 232 moniker. So that caused me no end of confusion until I finally worked it out with the always helpful Wikipedia. Thanks to John sorting out my stupid mistakes and lending me a scope and protoboard, I've since started to make progress.

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