Bootloader for Arduino Mega2560

The standard Arduino bootloader uses STK500 version 1 protocol. This protocol works fine up to chips that have 128 bytes of Flash. After that it does not understand the extended addressing. Fotuneatly there is STK500v2 protcol that can handle larger memory footprints.

I started with the wiring project stk500 v2 bootloader and modified it to work with the 2560.

This bootloader has been tested on

CPU	BOARD	Web site
atmega2560	Arduino mega
atmega1280	Arduino mega
atmega128	Amber128	http://www.soc-robotics.com/
atmega32	Penguino-AVR	http://www.icy.com.au/
atmega2561	Boston Android	http://www.bostonandroid.com/EVAL-USB-2561.html

It should be able to be made to work with any larger atmega cpu by modifiying the make file which is included with the source.

How to use the 2560 and others in Arduino

Download new Arduino core files
Update eeprom.h
Click here for eeprom.h.zip
It must be placed in hardware/tools/avr/avr/include/avr.>
On the MacOSX, the full path is /Applications/Arduino.app/Contents/Resources/Java/hardware/tools/avr/avr/include/avr
Restart Arduino software

The current bootloader in the Arduino mega board has a little known fact that it has a monitor built in. It is not very usable in that it has to be done with a program and cannot be used via a terminal because it uses binary commands. In order to access this "monitor" you have to open the serial port at 57600 baud and type "!!!" before it jumps to the main program.

I have done the same thing in the new bootloader but it is a command prompt to allow you to look at the hardware and memory. To access this monitor open up a serial port at 115200 and type "!!!" within 3 seconds.

The commands are

0=Zero address counters
?=CPU stats
@=EEPROM test
B=Blink LED
E=Dump EEPROM
F=Dump FLASH
H=Help
L=List available Ports
Q=Quit and jump to user program
R=Dump RAM
V=show interrupt Vectors
Y=Port blink

This bootloader takes 8K memory and I have used almost every available byte. The monitor can be turned of but this was designed for the atmega2560, atmega1280, and atmega128, all of which have plenty of flash memory space.

The monitor is VERY useful to test hardware. For example you can blink any port, you can look at flash, ram and eeprom.

Sample output



Arduino Bootloader>? CPU stats
Arduino explorer stk500V2 by MLS
Compiled on  = Aug  2 2010
CPU Type     = ATmega2560
__AVR_ARCH__ = 6
GCC Version  = 4.3.3
AVR LibC Ver = 1.6.7
CPU signature= 1E9801
Low fuse     = FF
High fuse    = D8
Ext fuse     = FD
Lock fuse    = FF
Arduino Bootloader>

ATmega2560
V#   ADDR   op code     instruction addr   Interrupt
01 - 0000 = C5 95 00 00 rjmp  0595 >000B2A RESET
02 - 0002 = C5 C0 00 00 rjmp  05C0 >000B84 INT0
03 - 0004 = C5 BE 00 00 rjmp  05BE >000B84 INT1
04 - 0006 = C5 BC 00 00 rjmp  05BC >000B84 INT2
05 - 0008 = C5 BA 00 00 rjmp  05BA >000B84 INT3
06 - 000A = C5 B8 00 00 rjmp  05B8 >000B84 INT4
07 - 000C = C5 B6 00 00 rjmp  05B6 >000B84 INT5
08 - 000E = C5 B4 00 00 rjmp  05B4 >000B84 INT6
09 - 0010 = C5 B2 00 00 rjmp  05B2 >000B84 INT7
10 - 0012 = C5 B0 00 00 rjmp  05B0 >000B84 PCINT0
11 - 0014 = C5 AE 00 00 rjmp  05AE >000B84 PCINT1
12 - 0016 = C5 AC 00 00 rjmp  05AC >000B84 PCINT2
13 - 0018 = C5 AA 00 00 rjmp  05AA >000B84 WDT
14 - 001A = C5 A8 00 00 rjmp  05A8 >000B84 TIMER2 COMPA
15 - 001C = C5 A6 00 00 rjmp  05A6 >000B84 TIMER2 COMPB
16 - 001E = C5 A4 00 00 rjmp  05A4 >000B84 TIMER2 OVF
17 - 0020 = C5 A2 00 00 rjmp  05A2 >000B84 TIMER1 CAPT
18 - 0022 = C5 A0 00 00 rjmp  05A0 >000B84 TIMER1 COMPA
19 - 0024 = C5 9E 00 00 rjmp  059E >000B84 TIMER1 COMPB
20 - 0026 = C5 9C 00 00 rjmp  059C >000B84 TIMER1 COMPC
21 - 0028 = C5 9A 00 00 rjmp  059A >000B84 TIMER1 OVF

Arduino Bootloader>L List available Ports
PORTA
PORTB
PORTC
PORTD
PORTE
PORTF
PORTG
PORTH
PORTJ
PORTK
PORTL
Arduino Bootloader>

Arduino Bootloader>R Dump RAM
0000 - 00 00 20 02 87 20 10 10 08 00 00 00 00 00 0E 00 .. .. ..........
0010 - 00 00 00 E3 00 00 20 00 2E 10 01 02 86 20 1E 00 ...... ...... ..
0020 - 00 00 00 80 80 80 00 00 00 07 00 00 03 00 00 00 ................
0030 - 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0040 - 00 FF 00 00 00 00 00 00 00 00 00 00 00 00 00 62 ...............b
0050 - 30 00 62 00 07 00 62 00 62 62 62 07 01 86 20 02 0.b...b.bbb... .
0060 - 00 00 62 62 00 00 88 62 00 00 00 00 00 00 00 00 ..bb...b........
0070 - 00 00 00 00 00 00 62 62 00 00 00 00 00 00 00 00 ......bb........
0080 - 00 00 00 62 00 00 00 00 00 00 00 00 00 00 62 62 ...b..........bb
0090 - 00 00 00 62 00 00 00 00 00 00 00 00 00 00 62 62 ...b..........bb
00A0 - 00 00 00 62 00 00 00 00 00 00 00 00 00 00 62 62 ...b..........bb
00B0 - 00 00 00 00 00 62 00 62 00 F8 FE FF 00 00 62 62 .....b.b......bb
00C0 - 22 18 06 62 10 00 6C 62 20 00 06 62 00 00 00 62 "..b..lb ..b...b
00D0 - 20 00 06 62 00 00 00 62 62 62 62 62 62 62 62 62  ..b...bbbbbbbbb
00E0 - 62 62 62 62 62 62 62 62 62 62 62 62 62 62 62 62 bbbbbbbbbbbbbbbb
00F0 - 62 62 62 62 62 62 62 62 62 62 62 62 62 62 62 62 bbbbbbbbbbbbbbbb
Arduino Bootloader>

June 2010

Version 1 2560 bootloader

NOTE: This version only suppors up to 128K program

In order to use the Mega2560 from Emartee in China, you need to make these changes to the Arduino environment. You will also need an ISP programmer

In the folder hardware -> arduino is a filed called "boards.txt"
On the Mac, this is Applications -> Arduino.app -> Contents -> Resources -> Java -> hardware
Add the boards section below to the end of "boards.txt"
Place the ATmegaBOOT_168_mega2560.hex.zip file in this folder (unzip it of course)
Applications -> Arduino.app -> Contents -> Resources -> Java -> hardware -> arduino -> bootloaders -> atmega
Replace the core files with this file arduino.zip
First you should rename the old one to ardino.old, the path is Applications -> Arduino.app -> Contents -> Resources -> Java -> hardware -> arduino -> cores -> arduino
Re-start the Arduino application
From the Tools -> Board menu select "Arduino Mega2560"
Connect your ISP programmer to the Mega2560 board
From the Tools -> Burn Bootloader menu select the appropriate ISP programmer

When you do the burn, most likely you will get the following error, you can igore it

		avrdude: verification error, first mismatch at byte 0x3e000
		         0x0d != 0xff
		avrdude: verification error; content mismatch

Now you should be able to use the Mega2560 just like any other Arduino board.

If you want the updated source and make file, CLICK HERE

add this to boards.txt

##############################################################
#	Added for Emartee in china
#	by Mark Sproul msproul@skychariot.com June 2010
mega2560.name=Arduino Mega2560
mega2560.upload.protocol=stk500
mega2560.upload.maximum_size=258048
mega2560.upload.speed=57600
mega2560.bootloader.low_fuses=0xFF
mega2560.bootloader.high_fuses=0xD8
mega2560.bootloader.extended_fuses=0xFD
mega2560.bootloader.path=atmega
mega2560.bootloader.file=ATmegaBOOT_168_mega2560.hex
mega2560.bootloader.unlock_bits=0x3F
mega2560.bootloader.lock_bits=0x0F
mega2560.build.mcu=atmega2560
mega2560.build.f_cpu=16000000L
mega2560.build.core=arduino