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[on:]

Hi friends

I have a few questions about using the Arduino Uno Rev3 as an In-System Programmer.

#Does the Reset pin hack, where the reset pin is held high using 120 ohms resistor, works?
If not, how do we do it then?
http://arduino.cc/playground/Main/DisablingAutoResetOnSerialConnection

#After the bootloader is burned, do we have to remove the microcontroller from Uno Rev3 in order to load the sketch as described here...
(I am looking at the minimal circuit)
http://arduino.cc/en/Tutorial/ArduinoToBreadboard

#Any way of using the above mentioned breadboard tutorial to program Atmega8?

Thanks for your time  :-)
Andy.

[Reply #1 on:]

#Does the Reset pin hack, where the reset pin is held high using 120 ohms resistor, works?
If not, how do we do it then?

I hear it does, many people suggest a 10 or so uf capacitor though as its better at absorbing the reset signal, something that big is bound to be polarized so stick the + end on 5 volts and the - end on the reset pin, other than that it's just plugging it into the header

#After the bootloader is burned, do we have to remove the microcontroller from Uno Rev3 in order to load the sketch as described here...
(I am looking at the minimal circuit)

if you want to program it using the serial port on the chip yes, or you have to come up with an external USB to serial adapter, or whats called a level shifter to use it on a real serial from your computer (which is -12v for 1 and +12v for 0, aside from being backwards thats 24 volts on a 5 volt part, but you can rig one together using some transistors and resistors)

#Any way of using the above mentioned breadboard tutorial to program Atmega8?

yea no problem, if your using an atmega8 with a 16MHz crystal and using the serial port bootloader to upload software you just need to choose Arduino NG or older w/ ATmega8, if you just want to keep it on a board and use the ISP as a programmer its a minor change in boards.txt

if your using it with no crystal you need to change the boards.txt so that the fuses are set correctly, if you want to ditch the bootloader which can suck up some valuable storage space on a pretty tight part, and use the ISP to program it ... we will get into that later for now as it can be tricky, and there is a small risk of "bricking" your chip (you can reset it but then you need extra crap to reset it and it turns into a big mess if your not setup for it)

though once you have an arduino loaded up with an ISP programmer sketch you can pretty much use any 8 bit atmel chip you please

[Reply #2 on:]

Hello!

I've followed the instructions from this page http://arduino.cc/en/Tutorial/ArduinoISP and doesn't work! When I plug the new Atmega328 in my Arduino Uno board and I try to upload a sketch it says this:   " avrdude: stk500_getsync(): not in sync: resp=0x00 " I've tried several times but without any results.

Does anyone knows the solution?

Thank you!

[Reply #3 on:]

" avrdude: stk500_getsync(): not in sync: resp=0x00 "

It means there's some problem with resetting.

[Reply #4 on:]

So what should I do?

[Reply #5 on:]

So what should I do?

do you have the setup with external crystal or you are using the internal clock on ATmega8.

[Reply #6 on:]

If I use the setup with external crystal, I can burn it BUT when I replace the chip from my Arduino Uno Rev3 with that I've just burned, doesn't work. It says " avrdude: stk500_getsync(): not in sync: resp=0x00 ".

If I use the other setup (without crystal) I can't even burn it. When I try, it says this:
avrdude: Yikes!  Invalid device signature.
         Double check connections and try again, or use -F to override
         this check.

Thank you for helping me!