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[on:]

Hi,

I recently fried my Arduino UNO. It isn't detected when I connect it to PC.
For troubleshooting, I want to upload the bootloader on a new Atmega328 chip using USBtinyISP programmer and replace the fried Arduino chip.
Almost everywhere, including ladyada's site, it mentions how to upload with the blank chip inserted in the arduino board(which might also be fried) using a programmer.
Is there a simple way of uploading bootloader using only a breadboard with USBtinyISP?
Also, if it doesn't work out, how do I remove the bootloader?

-Antzy

[Reply #1 on:]

Sure, put the chip on a solderless breadboard with the needed support components.
If it doesn't work out, just reprogram it again. They're made to be flexible like that

See 3rd picture here
http://www.dipmicro.com/store/CPU-ARD328P

[Reply #2 on:]

Thanks CrossRoads.

I found this link which provides bootloader hex file locations with fuse settings(table at bottom of page):
http://www.estechnical.co.uk/case-studies/50-embedded-devices-and-software/90-atmega-fuses-and-arduino-bootloaders

Planning to flash ATmega328P with Optiboot with following settings provided in the page:
Clock Speed   Unlock bits   Lock bits   Low Fuse   High Fuse   Extended fuse   Bootloader
  16MHz               0x3F           0x0F           0xFF             0xDE              0x05            optiboot/optiboot_atmega328.hex

[Reply #3 on:]

Those values seem to agree with the settings used for an Uno in boards.txt

Code:

uno.name=Arduino Uno
uno.upload.protocol=arduino
uno.upload.maximum_size=32256
uno.upload.speed=115200
uno.bootloader.low_fuses=0xff
uno.bootloader.high_fuses=0xde
uno.bootloader.extended_fuses=0x05
uno.bootloader.path=optiboot
uno.bootloader.file=optiboot_atmega328.hex
uno.bootloader.unlock_bits=0x3F
uno.bootloader.lock_bits=0x0F
uno.build.mcu=atmega328p
uno.build.f_cpu=16000000L
uno.build.core=arduino
uno.build.variant=standard

[Reply #4 on:]

And also with the optiboot makefile:

Code:

atmega328_isp: atmega328
atmega328_isp: TARGET = atmega328
atmega328_isp: MCU_TARGET = atmega328p
# 512 byte boot, SPIEN
atmega328_isp: HFUSE = DE
# Low power xtal (16MHz) 16KCK/14CK+65ms
atmega328_isp: LFUSE = FF
# 2.7V brownout
atmega328_isp: EFUSE = FD
atmega328_isp: isp

(EFUSE == 0xFD is the same as 5, depending on whether the "unused" bits are set to 1 or 0.)