So, looking around, you can pickup ATMEL atmega328p-pu MCU(s) for a pretty low price. If you want the Arduino bootloader pre-flashed, that's an extra $1+ per chip. Figuring I can just do it myself, I went a bought a bunch from JameCO of California.
Arduino UNO: The AVRisp exception
So, on the Arduino.cc site, there is an awesome page for how to use an Arduino board as an AVR ISP programmer for another Arduino: http://arduino.cc/en/Tutorial/ArduinoISP
However, at the top of the page, there is a gotcha:
NOTE: Currently, you cannot use an Arduino Uno as an ISP programmer because the optiboot bootloader does not support this sketch. A revision for this is in progress.So... after hitting many sites, building countless ISP or bypass circuits on breadboards, and basically banging my head against the wall, I visited this site for the umpteenth time:
And instead of trying to build a breadboard of the ISP circuit, I actually did something reasonable: I read the source code notes provided by WestfW, who wrote the OptiLoader, and you will note it says:
// If the aim is to reprogram the bootloader in one Arduino using another// Arudino as the programmer, you can just use jumpers between the connectors// on the Arduino board. In this case, connect:// Pin 13 to Pin 13// Pin 12 to Pin 12// Pin 11 to Pin 11// Pin 10 (of "programmer") to RESET (of "target" (on the "power" connector))// +5V to +5V and GND to GND. Only the "programmer" board should be powered// by USB or external power.
OMG!! Well, since I actually had 2 Arduino UNO boards, I made the hookups and plugged in a handle AC adapter. Voila! It flashed the chip in the other board! I tested uploading the blink sketch to the newly Arduino turned chip, and it accepted it. Amazing!
So, for the countless folks out there who are otherwise happy owners of the Arduino UNO board and just want to turn a blank atmega328 into an Arduino atmega328, give OptiLoader a try. It rocks.
Note, the OptiLoader sketch handles putting the optiboot loader onto more than just atmega328(s). Check out the source code for a complete list.
Happy photo gear hacking!