I haved designed a board compatible with Diecimila(ATmega168). I do connect DTR pin of FTDI chip to reset pin of ATmega168. However I found that I still need to press the reset button after clicking upload icon in arduino environment.
My question is: how to upload the firmware without pressing reset button?
You could check the Diecimilla schematics and see where your circuit differs from theirs.
The schematic shows both DTR# and RTS# from the FTDI FT232RL chip being connected to the Reset line through resistors marked "100_NM" (whatever that means).
I haved designed a board compatible with Diecimila(ATmega168). I do connect DTR pin of FTDI chip to reset pin of ATmega168. However I found that I still need to press the reset button after clicking upload icon in arduino environment.
My question is: how to upload the firmware without pressing reset button?
Thanks for any comments or suggestions.
HHPP
Many other designs also use the simple .1ufd series cap between FTDI DTR/ pin and the AVR reset pin successfully. Can you post a drawing of your design to see what might be preventing auto-reset function from working?