Optiboot on atmega328p using internal oscillator @ 8mhz

[Roger Unwin]

Hi,

I am having trouble working out the configuration to get optiboot to
work using the 8mhz internal oscillator. Is this something you might
know how to configure?

The config for 8mhz no crystal/resonator for the atmega328p that I
have confirmed to work is....
atm328int8.name=ATmega328 internal oscillator 8 MHz
atm328int8.upload.protocol=stk500
atm328int8.upload.maximum_size=30720
atm328int8.upload.speed=57600
atm328int8.bootloader.low_fuses=0xE2
atm328int8.bootloader.high_fuses=0xDA
atm328int8.bootloader.extended_fuses=0x05
atm328int8.bootloader.path=atmega
atm328int8.bootloader.file=ATmegaBOOT_168_atmega328_pro_8MHz.hex
atm328int8.bootloader.unlock_bits=0x3F
atm328int8.bootloader.lock_bits=0x0F
atm328int8.build.mcu=atmega328p
atm328int8.build.f_cpu=8000000L
atm328int8.build.core=arduino

Thanks,

Roger

[Brian O.]

Hey Roger,

You might need to edit the Makefile and add your own atm328int8 and
atm328int8_isp entries. I was able to get the bootloader flashing on
an ATmega324p with the following..

atmega324p: TARGET = atmega324p
atmega324p: MCU_TARGET = atmega324p
atmega324p: CFLAGS += '-DLED_START_FLASHES=5' '-DBAUD_RATE=115200'
atmega324p: AVR_FREQ = 8000000L
atmega324p: LDSECTION = --section-start=.text=0x3e00
atmega324p: $(PROGRAM)_atmega324p.hex
atmega324p: $(PROGRAM)_atmega324p.lst

atmega324p_isp: atmega324p
atmega324p_isp: TARGET=atmega324p
atmega324p_isp: MCU_TARGET=atmega324p
atmega324p_isp: HFUSE=DC
atmega324p_isp: LFUSE=E2
atmega324p_isp: EFUSE=FF
atmega324p_isp: isp

Regards,
Brian.

[Brian O.]

Hey Roger,

You might have to edit the Makefile to add sections atm328int8: and
atm328int8_isp: according to the other targets. I was able to flash
the bootloader on an ATmega324p with the following settings...

atmega324p: TARGET = atmega324p
atmega324p: MCU_TARGET = atmega324p
atmega324p: CFLAGS += '-DLED_START_FLASHES=5' '-DBAUD_RATE=115200'
atmega324p: AVR_FREQ = 8000000L
atmega324p: LDSECTION = --section-start=.text=0x3e00
atmega324p: $(PROGRAM)_atmega324p.hex
atmega324p: $(PROGRAM)_atmega324p.lst

atmega324p_isp: atmega324p
atmega324p_isp: TARGET=atmega324p
atmega324p_isp: MCU_TARGET=atmega324p
atmega324p_isp: HFUSE=DC
atmega324p_isp: LFUSE=E2
atmega324p_isp: EFUSE=FF
atmega324p_isp: isp

Regards,
Brian.

On Jun 3, 12:11 am, Roger Unwin <roger.un...@gmail.com> wrote:

[Teeh]

Hi,

I'm wiring a ATmega8L (8k) at 8 MHz, to make a minimal Arduino powered
by cell phone battery 3.6V.
The 512 bytes optiboot is perfect but I'm not sure about wich setup/
code use for it (ATmega8L), any 8 MHz will work?
What the minimal functional hardware support needed?

Thanks and Regards

Alvaro.