Hello,
I have just built uDuino [1] and parallel programmer [2].
I wanted to burn a bootloader with Arduino software into it (I also tried "avrdude") but I got an error saying that the "device's signature is invalid". Later it wont even say the signature is invalid - it now says that "AVR device not responding".
I thought I have too strong resistors in the programmer, I removed them - didn't help. I rewired everything - didn't help. So I got scared that I burned my first ATmega while the programmer was without the resistors.
But then I tried "uisp" and everything works! I compile a short sketch upload, verify, and the led blinks [3]! I can even erase the flash.
Please, can someone explain to me what's going on here? Why was avrdude saying the signature was invalid (I checked the wires 10x) and all of sudden it says that the device is not responding? Why is uDuino not working with Arduino software (or avrdude)? Maybe some electronics is missing or some cables but I checked a few schematics and all of the "seemed" to work with just a resonator, resistor on RESET and perhaps a capacitor between pin 7 and 8. Also, I read somewhere that "dapa" should not be able to reprogram the chip more than once - which is not the case here...
[1] http://www.instructables.com/id/S0DIQESFB7FYOJB/
[2] http://www.arduino.cc/en/Hacking/ParallelProgrammer
[3] Arduino Playground - CLI