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Schematic Design Review - Capacitive Touch Sense and Xbee

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Noggin

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I've started working on a home project, I don't know how far I'm actually going to go with it as I'm notorious for starting projects and not finishing them. One of the components required is a wireless keypad. I'd like to get a couple sets of eyes on it to see if I missed anything.

The end result of this project is a home security system. Depending on how far I get, I may post layouts and some basic code so that others can replicate the project.

This part of the system is the keypad where you enter your arming and disarming codes. It uses capacitive touch sensors arranged as a row and column scan pattern. It will then transmit through the Xbee to the base station. It has two inputs that can be attached to something simple like a reed switch to detect a door opening. This unit would then send a trip alert to the base station. The user would have 30 seconds to enter their disarm code before the alarm sounds.

I chose Xbee because there will be multiple keypads, multiple sensors, and a base station. Using Xbee will make it almost trivial to network everything together in the house.

3 keypads, 3 sensors, 1 home base, the xbee cost will be about $200 alone. That might be high enough cost to derail everything unless I figure out another radio option.
 

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Noggin

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Just realized that the I'll need to use the Vref pins for an analog reference so that my ADC can be used to read the ROWs and COLs. No biggie, I can use PGEC and PGED as off board IO.
 
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