Template ATmega328p project to use in Eclipse. It is already configured to be debugged with AVR Dragon

On arduino Uno ICSP connector :

1-MISO 2-+5V 3-SCK 4-MOSI 5-/Reset 6-Gnd

On AVRDragon :

AVR Dragon and UNO connected :

DebugWire uses reset line in order to flash/debug small MCUs like ATmega328 To enable debugWire with ATmega328p :

avrdude -pm328p -cdragon_isp -Pusb -v -U hfuse:w:0x9E:m

To disable debugWire with ATmega328p :

avrdude -pm328p -cdragon_isp -Pusb -v -U hfuse:w:0xDE:m

avrdude	-pm328p -carduino -P/dev/ttyACM0 -b115200 -Uflash:w:your_image.hex:a

avrdude -pm328p -c dragon_isp -Pusb -v -U flash:w:arduino_avr_template_avr_plugin.hex:i

When flashing using ISP with debugWire enabled, it will temporarily activate ISP and then debugwire is only possible after power-cycle. Consequently, in order to use avarice, MCU must be powered off/on

debugWire must be enabled

avrdude -pm328p -c dragon_isp -Pusb -v -U flash:w:arduino_avr_template_avr_plugin.hex:i

Flashing using debugWire isn't reliable => lot of mismatch error

debugWire must be enabled

Avarice must be first started :

avarice --debugwire --dragon --ignore-intr :4242

Then launch avr-gdb :

avr-gdb your_image.elf

then in gdb

target remote localhost:4242

Following steps must be done to debug with ATmega328p :

• Write Code in Eclipse, build without errors

• Upload to Arduino over usb-serial in Eclipse

• Enable DebugWIRE on Arduino with AVRDUDE

  avrdude -pm328p -cdragon_isp -Pusb -v -U hfuse:w:0x9E:m

• Start AVARICE

  avarice --debugwire --dragon --ignore-intr :4242

• Configure and start up debugging in Eclipse

• Debug until your eyes cross

• Disable DebugWIRE when done

  avrdude -pm328p -cdragon_isp -Pusb -v -U hfuse:w:0xDE:m

• then in gdb :

  target remote localhost:4242

(from excellent http://awtfy.com/2012/03/29/hardware-debugging-the-arduino-using-eclipse-and-the-avr-dragon/ )

To read fuse :

avrdude -pm328p -cdragon_isp -Pusb

ATmega328p only supports debugWire (1 wire debugging on Reset pin). To enable it, debugWire fuse must be set.

• default config used in arduino uno (defined in boards.txt of arduino ide):

• uno.bootloader.low_fuses=0xff

• uno.bootloader.high_fuses=0xde

• uno.bootloader.extended_fuses=0x05

• enable ATmega328p debugWire

  avrdude -pm328p -cdragon_isp -Pusb -v -U hfuse:w:0x9E:m

• disable ATmega328p debugWire

  avrdude -pm328p -cdragon_isp -Pusb -v -U hfuse:w:0xDE:m

• bootloader source / images can be found here https://github.com/arduino/Arduino/tree/master/hardware/arduino/bootloaders

• select your bootloader (mini bootloader in /atmega folder did not worked, prefer /optiboot bootloaders)

• disable debugWire fuse if enabled

  avrdude -pm328p -c dragon_isp -Pusb -v -U flash:w:yourbootloader.hex:i

Then you will be able to flash through Serial :

avrdude -pm328p -carduino -P/dev/ttyUSB0 -b115200 -Uflash:w:your_file.hex:a

Some external tools are in tools/eclipse_external_tools.

• flash_avr_template_328p.launch : read debugWire fuse, if set unset it, then flash code
• debug_avr_template_328p.launch : read debugWire fuse, if unset set it, then start avarice, after a debug session can be started

• debugging very slow : get avarice trunk version and compile it

  • on Arch https://aur.archlinux.org/packages/avarice-svn/
  • or directly from svn repo : http://sourceforge.net/p/avarice/code/HEAD/tree/trunk/

• restart program execution, set PC to 0, in gdb

  (gdb)set $pc = 0x00 (gdb)c

• "no debug symbol" when debugging

  • enable "-g2" debug flag
  • enable "-gstabs" or "-gstabs+" gcc options

• strange debugging : if you can, do not optimize code

• on Arduino mini set uart speed to 115200bps if you have this message

avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x00 

• when some code has been flashed with debugWire enabled using ICSP, MCU must be restarted

• Check wire pictures!!!

http://www.avrfreaks.net/forum/avrdragon-debugwire-atmega328p-nice-unusable

http://sourceforge.net/p/avarice/mailman/message/33130047/

http://awtfy.com/2012/03/29/hardware-debugging-the-arduino-using-eclipse-and-the-avr-dragon/

http://playground.arduino.cc/code/eclipse

http://www.gammon.com.au/forum/?id=11643

http://avr-eclipse.sourceforge.net/wiki/index.php/Debugging