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[on:]

Hi,

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

[Reply #1 on:]

You could check the Diecimilla schematics and see where your circuit differs from theirs.

http://arduino.cc/en/uploads/Main/Arduino-Diecimila-schematic.pdf

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).

[Reply #2 on:]

resistors marked "100_NM" (whatever that means).

The "NM" means not mounted, as in not installed in production units.


Lefty

[Reply #3 on:]

Hi,

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?

Lefty

[Reply #4 on:]

I have attached my schematic capture.
Please let me know if you find anything wrong. Thank you Guys!

[Reply #5 on:]

I have attached my schematic capture.
Please let me know if you find anything wrong. Thank you Guys!

Try it without C-29. And if R-16 isn't just a piece of wire, replace it with a piece of wire.

Lefty

[Reply #6 on:]

Hi Lefty,

Thank you very much for your suggestion. I removed C29 and it works!!

Regards,
hhpp

[Reply #7 on:]

For completeness, see this post as well.