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[Reply #315 on:]

I wasn't sure what values OSCCAL could take, so I hedged my bets. The byte would have been wasted anyway as all opcodes are 2bytes long, so it does no harm being there and it acts as an extra measure of protection.

[Reply #316 on:]

The byte would have been wasted anyway as all opcodes are 2bytes long

When reading Flash as data it is byte-wise.  Check the LPM instruction for details.

[Reply #317 on:]

Ahh, you were thinking about reading the flag to check it. I was thinking about the byte of program memory it takes to store. If necessary it can be removed later, but at the moment doing so will not reduce the overall size of the bootloader as it will take up an integer number of 64 byte pages. As it stands, the bootloader takes up exactly 9 pages. If at some point more space us needed, I will remove that check.

[Reply #318 on:]

There is now a .zip file for Optiboot 5.0
There are no "important" changes for the core Arduino platforms in 5.0, but it does support the ATmega32, ATmega1284, and has a new makefile structure that should make it much easier to build custom version of optiboot from the source.
http://code.google.com/p/optiboot/downloads/detail?name=optiboot-v5.0.zip&can=2&q=

[Reply #319 on:]

Excellent!  Thank you!

[Reply #320 on:]

@westfw:
Just a suggestion. You should update the rev. number into the comments of the optiboot.c file .
The last modify is still marked as " Mar 2013 - 4.6" 

[Reply #321 on:]

@westfw:
i tried to install optiboot5 on IDE 1.5.2 (windows) in the hardware directory, inside the sketch directory, like your installation guide, but do not work

the "hardware directory method" it is valid for 1.5.x branch of IDE ?

[Reply #322 on:]

You should update the rev. number into the comments

oops!

[Reply #323 on:]

Code:

make atmega328 AVR_FREQ=16000000 BAUD_RATE=1000000

BAUD RATE CHECK: Desired: 1000000, Real: 1000000, UBRRL = 1, Error=0.0%
avr-gcc -g -Wall -Os -fno-inline-small-functions -fno-split-wide-types -mshort-calls -mmcu=atmega328p -DF_CPU=16000000  -DBAUD_RATE=1000000 -DLED_START_FLASHES=3       -c -o optiboot.o optiboot.c
optiboot.c:277:2: error: #error Unachievable baud rate (too fast) BAUD_RATE
make: *** [optiboot.o] Error 1

Argh!

[Reply #324 on:]

Why check for a UBRRn value below 3?  The new baud rate check traps troublesome combinations very nicely...


make atmega328 AVR_FREQ=16000000 BAUD_RATE=900000

BAUD RATE CHECK: Desired: 900000, Real: 1000000, UBRRL = 1, Error=-11.1%
avr-gcc -g -Wall -Os -fno-inline-small-functions -fno-split-wide-types -mshort-calls -mmcu=atmega328p -DF_CPU=16000000  -DBAUD_RATE=900000
optiboot.c:252:2: error: #error BAUD_RATE error greater than -5%
make: *** [optiboot.o] Error 1

[Reply #325 on:]

@westfw:
i tried to install optiboot5 on IDE 1.5.2 (windows) in the hardware directory, inside the sketch directory, like your installation guide, but do not work
the "hardware directory method" it is valid for 1.5.x branch of IDE ?

Sorry for the bump, may you confirm that it is not compatible with IDE 1.5x ?