next topic »

[Reply #15 on:]

I have already tried this, too.
Do you think that using avrdude directly without the ide could be a solution for the boot loader error?
I searched on web about this problem and I found another person who can upload a sketch only ones and was a problem with fuses...
This is the link: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1268700386/0

Thank you

[Reply #16 on:]

Do you think that using avrdude directly without the ide could be a solution for the boot loader error?

It is not a direct solution; the IDE runs AVRDUDE just as you would.  But using AVRDUDE would give you more control and may help isolate the problem.

Do you have another processor (like a DIP 328) + breadboard that you could use to prove that the software and ISP are working correctly?

[Reply #17 on:]

Give it a try, Remember to unlock the chip before writing the bootloader, and lock the chip when finished. also unplug the board and reinsert it after locking it.

Drew.

[Reply #18 on:]

From that other string:

"After programming the bootloader (with the STK500 programmer),  I remove the ISP cable and move the serial connector to the second DB9 on the STK500.  This port is cabled into the '328 via a 2 wire jumper (rx/tx).  I then use the Arduino IDE to upload the sketch.  It works once, but only once."

If that is what you are doing, using a serial connection to upload sketches and not the ICSP connection, you need to manually reset the target system just before the sketch loads.  That is what the auto-reset on the Arduino does for you. To implement auto-reset on a target machine you need the DTR signal from the PC to get to the reset pin through a capacitor.

[Reply #19 on:]

In my board there is the FT232 and I have connected the DTR pin just like in the arduino board.
This is the circuit:

IC11 is the FT232 and C33, C28 are both 100nF.

Thank for your help!

[Reply #20 on:]

I just looked at the Arduino Mega 2560 reference design schematic (http://arduino.cc/en/uploads/Main/arduino-mega2560-schematic.pdf) an they use a 22pf capacitor to connect Reset to ground where you are using 100nf (your C28).  I wonder if that might be enough to make auto-reset not work or not work reliably.

[Reply #21 on:]

That's it!! 
Now it works!

Thank you very much!!

Andrea