Connecting the Bootloader Monitor on a Mega 2560 r3 failed

I am trying to connect the Arduino IDE built in Serial Monitor with the bootloader monitor as described on this site.

http://avr-developers.com/bootloaderdocs/index.html

My set-up:

  • OS X 10.8.4
  • Mega 2560 r3
  • Arduino IDE 1.0.5
  • 115200 baud
  1. I type “!!!”
  2. Reset the board and click the send button

I got a connection to the bootloader monitor but the output is not readable.

What can I do?

SerialMonitor.jpg

Your Mega2560R3 board is using the latest stk500v2 bootloader from IDE 1.0.4/1.0.5. Don't know what exactly they changed but the Serial Monitor mode has never worked correctly since the "latest" fixes.

If you put back the older version bootloader from IDE 1.0.3 or older then you will be able to use the Serial Monitor mode "!!!". The older version is also in the IDE 1.0.4/1.0.5, \hardware\arduino\bootloaders\stk500v2\Mega2560-prod-firmware-2011-06-29.hex.

Thanks, it works with the older version.

The version included in Arduino 1.0.3 is dated Aug 26. 2010:

...
//*	Jul 29,	2010	<MLS> Added recchar_timeout for timing out on bootloading
//*	Aug 23,	2010	<MLS> Added support for atmega2561
//*	Aug 26,	2010	<MLS> Removed support for BOOT_BY_SWITCH

The version included in Arduino 1.0.4 and 1.0.5 is dated Jan 1, 2012:

...
//*	Aug 26,	2010	<MLS> Removed support for BOOT_BY_SWITCH
//*	Sep  8,	2010	<MLS> Added support for atmega16
//*	Nov  9,	2010	<MLS> Issue 392:Fixed bug that 3 !!! in code would cause it to jump to monitor
//*	Jun 24,	2011	<MLS> Removed analogRead (was not used)
//*	Dec 29,	2011	<MLS> Issue 181: added watch dog timmer support
//*	Dec 29,	2011	<MLS> Issue 505:  bootloader is comparing the seqNum to 1 or the current sequence 
//*	Jan  1,	2012	<MLS> Issue 543: CMD_CHIP_ERASE_ISP now returns STATUS_CMD_FAILED instead of STATUS_CMD_OK
//*	Jan  1,	2012	<MLS> Issue 543: Write EEPROM now does something (NOT TESTED)
//*	Jan  1,	2012	<MLS> Issue 544: stk500v2 bootloader doesn't support reading fuses

I guess the Fix dated Nov 9, 2010 has changed the Serial Monitor Code.

Edit:

It’s quite strange: Arduino 1.5.2 contains the same version as Arduino 1.03!

It’s quite strange: Arduino 1.5.2 contains the same version as Arduino 1.03!

Why is that strange? Those two releases from from about the same timeframe; one is for Due/etc, and one is the AVR-only version.

This is the first I’ve heard that the serial monitor mode is broken in the latest version; the bugfix for Issue 392 should only stop !!! from entering the monitor during an actual upload. Sigh.

westfw:
This is the first I’ve heard that the serial monitor mode is broken in the latest version; the bugfix for Issue 392 should only stop !!! from entering the monitor during an actual upload. Sigh.

Obviously we had troubles with the latest version (Jan 1, 2012). Version (Aug 26, 2010) works for me (see attachment)
Did you try with a Mega 2560 r3?

Compare stk500boot.c included in Arduino 1.0.5 and 1.5.2 (…/arduino/avr/bootloader/stk500v2/stk500boot.c) and you’ll see the difference.

Mega2560r3Monitor.jpg

I got a connection to the bootloader monitor but the output is not readable.

i get this too