I built my own Arduino. Loaded firmware onto the 8U2, computer recognizes it as an Arduino Uno. Loaded optiboot_atmega328.hex onto the AtMega328. The AtMega328 is running @ 8Mhz on the internal clock.
Double checked that my serial connections are correct. I select "Arduino Uno" as the board and the proper COM port, and get this error when trying to upload a sketch: avrdude: stk500_getsync(): not in sync: resp=0x00
I have also added the following to boards.txt and did not have success using this board either:
atmega328_8.name=ATmega328 Optiboot (8 MHz internal clock) atmega328_8.upload.protocol=arduino atmega328_8.upload.maximum_size=32256 atmega328_8.upload.speed=57600 atmega328_8.bootloader.low_fuses=0xe2 atmega328_8.bootloader.high_fuses=0xde atmega328_8.bootloader.extended_fuses=0x05 atmega328_8.bootloader.path=arduino:optiboot atmega328_8.bootloader.file=optiboot_atmega328.hex atmega328_8.bootloader.unlock_bits=0x3F atmega328_8.bootloader.lock_bits=0x0F atmega328_8.build.mcu=atmega328p atmega328_8.build.f_cpu=8000000L atmega328_8.build.core=arduino:arduino atmega328_8.build.variant=arduino:standard
Do I need to run a specific version of optiboot for running at 8Mhz, or should I look into another problem?
As a side note, I thought AtMega8U2's were supposed to come from the factory with the internal oscillator fuse set. But the one I got was set to an external crystal and required one to start up. Is that normal?