Using Arduino Uno as ISP to program Mega 2560

Question

I'm trying to use Arduino Uno as ISP to program Arduino Mega 2560 using this Pin connections (Uno->Mega):

slave reset: 10: -> RESET on target

MOSI: 11: -> 51

MISO: 12: -> 50

SCK: 13: -> 52

It runs perfectly when I "Burn Bootloader" from Arduino IDE and LED starts blinking on target. So I assume my pin connections are correct.

However, when I open the Blink example and perform "Upload Using Programmer" in Sketch tab after choosing "Arduino as ISP" in Tools>Programmer it uploads the code but LED on Mega doesn't blink.

I'm afraid that I have problem in my Mega Bootloader hex file and think it's not configuring Pin 13 as a LED pin. But in this case I shouldn't have seen the led blinking after burning the bootloader.

What am I missing here? I appreciate your help. -Bex

Answer 1

Find the file called "boards.txt" located in your Arduino installation directory. In my case, the path is "arduino-1.6.5/hardware/arduino/avr/boards.txt". Open it with your favourite text editor and locate the ATMEGA2560 section. (not in notepad, it breaks the file format, notepad++ my choice)

in boards.txt

• back-up the file incase you break it,
• find the line : mega.menu.cpu.atmega2560.bootloader.high_fuses=0xD8
• and change it with : mega.menu.cpu.atmega2560.bootloader.high_fuses=0xD9

Source : http://soc.ninja/documentation/programming-atmega2560-with-arduino-uno-or-mega/#rating-74