Re: Sanguinololu Rev 1.3a - how to load firmware

an avrisp is additional hardware, commonly another ardunio running isp firmware


since you don't have this your limited to option 1


Yes baudrate is a possibility

you need to find the boards.txt file it contains a section

###### ATmega1284x

## Sanguino W/ ATmega1284 or ATmega1284P 16MHz
sanguino.menu.cpu.atmega1284p=ATmega1284 or ATmega1284P (16 MHz)

sanguino.menu.cpu.atmega1284p.upload.maximum_size=130048
sanguino.menu.cpu.atmega1284p.upload.maximum_data_size=16384
sanguino.menu.cpu.atmega1284p.upload.speed=115200

sanguino.menu.cpu.atmega1284p.bootloader.file=optiboot/optiboot_atmega1284p.hex

sanguino.menu.cpu.atmega1284p.build.mcu=atmega1284p
sanguino.menu.cpu.atmega1284p.build.f_cpu=16000000L

you can try changing
sanguino.menu.cpu.atmega1284p.upload.speed=115200
to other speeds, I've see bootloaders use 38400 and 57600
NB you need to restart the ardunio IDE program after you change this file. It only reads it on start up.

Sadly there is no way to know what baud rate it expects, no one seems to document their boot loader.
Also some cheap suppliers dont bother installing a bootloader, so there is no way to make it work with avrisp hardware

NB this baud rate is not related to the baud rate you set in marlin configuration.h that is for marlin only.