I know that the arduino Diecimila comes with an Atmega168, which it programs, but it looks like the chip is removable and can be used in a separate cricuit and another one can be put into there. In this sense, I think of the Diecimila as a "Programmer"(A "bootloader" might be a more appropriate term, but I don't know the technical difference(s).). So I take it the Diecimila can 'program' multiple Atmega168 chips? If so, can it program other chips like an Atmega88 or Atmega48 which are of the same form factor? Can it program any other chips with relatively minor modifications?
I think it might be nice to use my Diecimila for what may eventually evolve into commercial purposes(And for my own uses with multiple chips in their own special circuits), and using the lowest-cost chips possible is kind of essential for competitiveness.
Yes, you can pull the ATmega168 (complete with its bootloader and uploaded sketch program) and use it in another PCB entirely.
There are some gaps in your understanding of it.
It is true that the Diecimilia board makes it easier to program the ATmega168. You can just upload the program into it, and it will start running. The Diecimilia board makes it easy to connect for prototyping. But the ATmega168 chip on a Diecimilia is not just a plain stock part straight from the maker. There is a mini-program on the chip that was uploaded once by the Arduino guys, and it is this permanent mini-program (the bootloader) what helps the uploading process for all future sketch programs over the USB connection. Many folks never replace the bootloader program with a custom one, but if you wanted to do so, you would have to use a different programming connection entirely, not the USB connection.
The Diecimilia board might be adapted for use with the ATmega8, the ATmega168 (the standard part), and maybe the new ATmega328, but I don't think it works for other varieties. It's not just the physical size and number of pins, but also the purpose for each pin, that matters.
So the bootloader installed by the Arduino folks on the Atmega168 chip allows it easy interaction and downloading from the Arduino program from the computer? But atmega168 chips do not usually have this boot-loader so the boot-loader would have to be installed with each new atmega168 chip. Correct?
If I'm reading correctly, that method detailed on the linked page allows one to use the diecimila to burn this needed boot loader to a new atmega168 chip(that doesn't have the boot loader) so one can use it in any diecimila like "normal" and regular pcb circuit? If so, I'll have to take a closer look at the linked page.
That does sound rather exciting if this boot loader was a limiting factor. I thought the diecimila was like a prototyping/programming combo so one could test and produce as many chips as wanted. At least I thought so since the chip looked like it could be easily removed and replaced from the DIP socket(as opposed to the other rather permanently installed surface-mounted components).
"It's not just the physical size and number of pins, but also the purpose for each pin, that matters."
I heard from google that 'The ATmega48, ATmega88 and ATmega168 differ only in memory sizes, boot loader support, and interrupt vector sizes.'(on the avr forums at http://www.avrfreaks.net/index.php?module=Freaks%20Devices&func=displayDev&objectid=78) so I assumed the pins weren't changed... I might be wrong as I haven't really checked the pin diagrams.
Yes you are right in your understanding of the bootloader. Not sure of the pins though. So if you work out the bootloader thing u can program your chips on the arduino board and then put them into other permanent circuits.
Remember, if you can buy the ATmega168 with the Arduino bootloader already loaded. This way you can just pop one out and another in and program, without having to burn the bootloader yourself. This route is certainly simpler. I'm not saying that you shouldn't burn your own bootloaders, but if you're only doing 1 or 2 extra chips, hardly seems worth the effort to mod the Diecimila.
I see preloaded 168s at adafruit.com for $6. I'm always happy to support Limor. She's given alot to the community, from the first mintyboost with the exceptional instructables on it, to the Arduino tutorials that jump started me on this platform.
let us know how it goes.
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