Uploading firmware: stk500_getsync problems

I have a Sanguinololu 1.3a and I've recently upgraded to a ATmega1284p. Last time I had time to work on the project (almost a year ago) it had a 644 and by fiddling with upload speed settings and the com port drivers I was eventually able to upload a Marlin build from a windows 7 machine. Since then I bought a panelolu2 and the 1284 (which came with a bootloader) and a new windows 8 machine. After getting it to be recognized on COM4 by windows and getting the new Marlin version and settings to compile without errors, I get the all to common error:

avrdude: stk500_getsync(): not in sync: resp=0x00

I've got the reset jump "on" but I've also tried holding the reset button with no luck. I've taken the baud rate down to 38400 in boards.txt (and restarted IDE) as suggested on the sanguinololu page and made sure that the windows com port speed is set the same but still get the error. I've even seen it suggested to change upload.protocol=arduino instead of stk500 so I tried that, but no luck.

Arduino 1.0.5-r2
ATmega1284p 16Mhz (matches what it says on the chip)
COM4

Here's the section from boards.txt as it appears right now:

atmega1284.name=Sanguino W/ ATmega1284p 16mhz

atmega1284.upload.protocol=stk500
atmega1284.upload.maximum_size=131072
atmega1284.upload.speed=38400

atmega1284.bootloader.low_fuses=0xD6
atmega1284.bootloader.high_fuses=0xDA
atmega1284.bootloader.extended_fuses=0xFD
atmega1284.bootloader.path=atmega
atmega1284.bootloader.file=ATmegaBOOT_168_atmega1284p.hex
atmega1284.bootloader.unlock_bits=0x3F
atmega1284.bootloader.lock_bits=0x0F

atmega1284.build.mcu=atmega1284p
atmega1284.build.f_cpu=16000000L
atmega1284.build.core=arduino
atmega1284.build.variant=standard

Any suggestions for this? Any ideas of what could be the problem? Any way of telling where the upload is getting stopped? (windows to USB, USB to serial chip, serial to ATmega...)
Thanks,
Bret

OK, I've been digging around with more google and forum searches and I've run across something that has generated more questions and I'm guessing that it doesn't matter, but thought I'd ask.

I installed the latest (non-beta) Arduino software and downloaded the latest Marlin firmware from github. I followed the directions to take the "Sanguino" directory from the Marlin-Marlin-V1/ArduinoAddons/Arduino_1.xx/hardware/directory into the Program Files(x86)/Arduino/hardware/ directory and it seems to have found it as the options show up under "tools-->boards".

But looking around the web I see lots of references to versions of Sanguino software revisions, but I don't see any revision information with the Marlin directories and I didn't download anything for official "Sanguino", just assuming the stuff that came with Marlin is sufficient. Here's the Sanguino official SW which hasn't been updated in a while and talks about much older Arduino versions: [sanguino.cc] My assumption is that all that is "old" and I should just stick with what Marlin has and says in the Readme file for installing Sanguino specific stuff. But then there are posts that talk about specific Sanguino revisions making the difference here: [forums.reprap.org]

Any suggestions about what to try?
Thanks,
Bret

atmega1284.upload.speed=38400 try 57600

different boot loaders have different upload bauds

Also check your enable auto reset jumper is on, the computer needs to reset the board to get into upload mode.

stk500_getsync(): is a communications error, basically its not getting the responses it needs

Edited 2 time(s). Last edit at 05/17/2014 01:31AM by Dust.

Thanks Dust. That was it. I think I have a newer bootloader and it's set for 57600. The default was 57600 in the boards.txt file, but I don't think I had the COM port set to match in windows. When that didn't work I searched the sanguinololu page and found the tip about changing to 38400 and matching that in the COM settings in windows. But that didn't work with the newer bootloader. But after putting boards.txt back and setting windows correctly it uploaded just fine.

Thanks for your help. Feeling a little stupid now, but at least it's working :-)
-Bret