It is late night, and your cellphone rings. You can't see where it is, you blindly grope around your nightstand, trying in vain to find that illusive switch that will illuminate your side of the bed. You clumsily turn on the lamp, locate your cellphone...and you miss the call. Damn. If only your light was easier to turn on.
What if all you had to do to turn on your lamp...was to touch anywhere metal on your bedside table? That sounds complicated though, and I AM a strong believer in keeping things simple whenever possible. I wonder if there are any open-source solutions that would allow such a thing to happen? Enter ARDUINO. A cheap, easy to use micro-controller that is dead simple to program and implement. This sounds like it might just work!
Since I am inherently thrifty (an HVAC-R apprentice, AND a Mennonite) I don't want to commit my only $35 arduino board to the project. This means i'll have to build my own Arduino, which will save me some money. Additionally, I'm only using a couple of pins, and not doing any serial communications, so I really don't want to bother using an external oscillator. That means I'll have to figure out how to enable the internal oscillator on an atmega 168.
This 'ible will show you how to do the following (without a lot of hand-holding);
How to burn a bootloader to a standalone atmega168 using an Arduino UNO SMD edition.
How to enable the internal oscillator, so you can save $0.50 and not use a crystal.
How to program a standalone chip using an Arduino board and the Arduino IDE.
How capacitive touch objects work.
What is NOT covered
How to read a schematic diagram
How to solder
How to layout a protoboard
Since there are literally hundred of guides on how to solder, how to use schematic diagrams, and basics of digital electronics...I'm not going to go there. You'll notice that there is a search bar in the upper right hand corner of this wonderful site. I'm sure if you try using it, you'll find what you need. That said, if you are having troubles implementing THIS particular project, and it doesn't involve such things as "How do I solder a resistor" then please feel free to ask.
I am curmudgeonly, so my responses to questions that are not included in the scope of this 'ible may or may not include some lighthearted mocking. You have been warned.
This is a proof of concept i'd put together before building the standalone.