*argh* So.. much.. conflicting.. information!

pulls out hair

I just started reading up on using the atmega168 chip in a stand-alone (without the Arduino-board) configuration. Could anyone shed some light on this for me, pleeeeaase? :-/ Btw, I have the newest Arduino Diecimilla.

Some documents say you have to buy/build a burner, some say you can use the Arduino board to burn the sketch right to the atmega168-chip, pull the chip out and hook it up, and some http://www.arduino.cc/en/Hacking/Programmer seem to suggest that with modifications to the Arduino Preferences file one can use the Arduino board as a full-fledged burner/programmer. That is, overwrite the bootloader and just write your program directly to the Arduino.

Also, the documentation I have seen uses a 16MHz crystal and some other simple components. Thing is, I think I remember reading that the atmega168 has a built-in oscillator that it uses if no external oscillator is added. Is this wrong, is the built in oscillator much slower or… am I just beeing a complete asshat? :stuck_out_tongue:

Thanks in advance for any help! ;D

If you program the 168 processor while it is in the Arduino board, them you can take it out and use it like this:

http://www.arduino.cc/en/Main/Standalone

The schematic shows the Atmega 8 processor but i believe that the 168 should work just the same.

Of course to reprogram the processor you would have to put it back in the Arduino board.

You don’t have to buy or build a burner to use an Arduino (and unless I’m much mistaken, it doesn’t actually say that anywhere). Buy an Arduino, download the IDE, happy hacking.

Since the Arduino is built in the spirit of open source, complete information for making your own Arduino (or Arduino-like) board is provided - all this info is probably the source of your confusion.

If you want to make your own Arduino-like device that can be programmed over a serial port using the Arduino IDE, then its ATmega needs to have a bootloader on it. You can either build/buy a programmer to burn the bootloader yourself, or you can buy an ATmega with the bootloader already burned.

With a very few programmers, the Arduino IDE can be used to burn the bootloader directly.

The Arduino IDE will not burn a program directly to the ATmega, without the bootloader.

The ATmega has several options for its clock source. An external crystal gives the best stability and the highest operating frequency compared to using the built-in RC oscillator. The Arduino software environment is designed for an external crystal at 16MHz, and the ATmega fuse bits are burned accordingly.

If you want to yank the ATmega from an Arduino board, make sure the target circuit has: a pull-up resistor on the RESET pin; regulated +5V at VCC and AVCC; a ground connection to GND and AGND; and a 16MHz crystal with appropriate capacitors on the XTAL pins. I may have forgotten some, but there is a forum thread on the subject.

The forum search stinks. Use google, and plug in “site:www.arduino.cc mysearchstring” (where mysearchstring is, of course, your actual search term) for much better search results.

Hope this gets you on the right track.

-j

Thanks loads! I’ll have to think about ordering up some Atmega168’s now… damnit! Cash… need to save… cash… christmas… strangeling wallet grgh

All I need now is a fairly reliable way to implement wireless 2-way communication, with atmega168-based devices having individual ID’s listening for commands or poll-requests from a central computer. Smoothest. Home automation system. Ever. ^^