weAutSys comes with a serial bootloader according to Atmel Corporation's application note AVR109.
For sake of transmission robustness it uses 38400 baud (38400N1). That makes the it a bit slower than a mySmartUSB light. Good conditions provided higher baud rates are feasible too.
The biggest advantage of this serial AVR109 bootloader integrated to weAutSys is no need for any extra programming hardware — not even those four jumpers for a bit banging ISP. The minus is not being able to modify some fuses or, of course, the bootloader itself. For most use cases that's more of a plus.
Please download and read
Albrecht Weinert
A serial bootloader for ATmega based products — weAut_01, Arduino and akin
This development report (English, .pdf) gives some background on ATmega architecture, bootloader, avr-gcc, bootloader linking and on some common errors and problems. One of those problems, well known with Arduinos and serial bootloaders, is e.g. the dreaded:
"avrdude: error: programmer did not respond to command: set addr"
or "... set extAdr" and suchlike.
Modules | |
Bootloader operation | |
Bootloader integration | |
Files | |
file | boot109.c |
Implementation of weAutSys' serial bootloader program. | |
file | boot109.h |
Definitions of weAutSys' bootloader and helper functions. | |
file | bootLib.c |
Implementation ofweAutSys' bootloader helper functions. |