Hi, I have been messing around with Arduino for a while and my question is: using the icsp programmer is it possible to program the chip without using the arduino bootloader? I under stand that i would have to remove the 16mhz clock since the chip is only made to run at 8mhz. My goal is to program the chip without the bootloader so I can just pull the chip out and put it in other projects. I would like to still be able to program in C/C++ like I have been, will I lose any functionality (other then processing). What modifications will I have to do to hardware/software to get this to work? Is there a way to do it so that I can use other members of the atmega family with the same setup? Thanks, nik
Sounds like you've got a few different questions. Let me try to answer them.
Yes, using an ICSP programmer you can program the chip without the Arduino bootloader, see http://www.arduino.cc/en/Hacking/Programmer for details. The chip can still run at 16 MHz (assuming you have a 16 MHz clock in your other circuit). You can still use the Arduino environment and the standard core libraries.
If you want to run the chip without an external clock, you'll need to make a few changes. You'll need to burn the correct fuses onto the chip to get it to run without an external clock. You'll also need to change the build.f_cpu setting in your Arduino preferences file to the correct value. A few things might not work properly.
For other atmega's you'll need to make changes to the Arduino core (in ARDUINO/lib/targets/arduino). Shouldn't be too hard, but will require lots of reading datasheets.
Hey, thanks for the quick response. How would I go about burning the arduino code directly onto the chip via the icsp. When i hit upload it does it via usb. Is there some option I can change? Thanks
What kind of ICSP programmer do you have?
the Avr-Isp from digikey
Did you select the serial port of the AVR-ISP from the Tools | Serial Port menu?