Re: [avr-chat] Please help on stk500_getsync() problem.

[Erik Christiansen]

On 23.10.15 07:42, Lasse Karagiannis wrote:
> avrdude.exe: stk500_getsync() attempt 1 of 10: not in sync: resp=0x3f
...
> Arguments:
> -C "C:\Program Files (x86)\Arduino\hardware\tools\avr\etc\avrdude.conf" -v
> -v -p m32u4 -c arduino -P COM6 -b 57600 -U
> flash:w:"$(ProjectDir)Debug\$(ItemFileName).hex":i
> 
> Initial Directory:
> $(ProjectDir)
> 
> Running Arduino Leornardo on ATMega32u4, my COM port is for Arduino
> Leornado is COM5, and my Arduino Leornado Bootloader
> is on COM6.

I haven't fiddled with the arduino toolchain, but instead blown away the
bootloader and just used the unit as a bare AVR development board with
avr-gcc, so haven't had that issue. However, it looks like arduino users
have found various ways to produce that type of error message:

http://www.instructables.com/id/A-solution-to-avrdude-stk500getsync-not-in-syn/

http://forum.arduino.cc/index.php?topic=28223.0

There are doubtless other google hits which describe causes and fixes,
and there are youtube clips on the subject - though they seem a tedious
way to fight your way to anything informative.

Your device seems to match, leaving correcting mismatched com ports,
pressing reset, and disconnecting RX, as potential fixes.

Good luck.

Erik