Also, how would the arduinoISP try to program itself?
The bootloader responds to AVRDUDE instead of the Arduino ISP Sketch. If autoreset is not disabled, the bootloader runs instead of te Arduino ISP Sketch. From AVRDUDE's perspective there is no difference. For our perspective there's a huge difference!
But the bootloader does not send the device ID, does it?
I have no idea if it does or not. AVRDUDE gets rather annoyed if the ID is not available or is not the expected value so I assume the bootloader has to send the processor's ID to satiate AVRDUDE.
Does the bootloader mimic the built-in serial interface?
By "built-in serial interface" I assume you mean the interface provided by the processor. In which case, I have no idea. I don't know anything about the on-processor interface.
I was not aware that the arduino IDE used AVRDUDE to upload programs. I thought the whole point of the bootloader was that you didn't need to use ICSP, considering that the arduino IDE uses serial to upload stuff... It just seems astronomically unlikely to me that the two protocols would line up so conveniently.
lol @ the misinformation here.... the IDE is just a wrapper for the avrdude program. the icsp pins on the uno are the six pins mounted right next to the chip. The usb port uses serial communication, I have a breadboard arduino and the only things hooked up to the FTDI cable are the serial ports, power, ground, and the auto reset pin. like Coding_Badly said, hold shift and click upload for any sketch and you see the avrdude output.
I had the auto reset disabled, but then I get sync errors. So I unplugged the reset wire, and still had issues, i have to hold the reset button on the uno and then let go when avrdude tried connecting to get anything now... who knows...
foxgt, no one here is misinformed... I'm not stupid, I've used ICSP and the arduino serial protocol, I know how these things work. What perplexes me is the fact that they (apparently) chose to make a bootloader for the sole purpose of using the default ICSP protocol over asynchronous serial. Using the default protocol literally takes 1 more pin, saves kilobytes of code and probably lots of time. Is there really any tangible gain to doing this? I can't think of any...
I have been able to write to the attiny85 using the arduino IDE, I just have to perform a manual erase with avrdude...
the -F doesn't really seem necessary if I can write to the chip without it... I don't think I can make the IDE use it by default, so it really won't save me any trouble.
I think this might be related to my laptop, it seems like others seem to have success with it... I'll try my desktop and see what happens, both are Windows 7 machines, but the laptop isn't cutting edge by any means...
lol... correct me if im wrong...To disable the auto reset I'm using two 220 ohm resistors in parallel, but that is when I get the sync errors. Two 220 ohm resistors in parallel is equivalent to 110 ohms... 1/(1/220 + 1/220).
I looked through those posts... I hadn't thought about putting a cap as well as the 5v to it... I'll try that as well and see if it helps me get around the sync errors I guess
edit: oops, thought I mentioned the 220 ohm resistors earlier, added that
If you have a serial cable with a level shifter (i.e. MAX232) you can just use that. Sine you only connect the Tx & Rx to the Arduino you will not get the reset. The ArduinoISP won't work if it resets when you load the sketch into the ATtiny. (Maybe you know that or am doing something else, reading this I'm a little confused.)