Presumably through carelessness while breadboarding I now have two 328s which won't upload any sketch. The green power LED and the yellow D13 LED are on. Both give the same error, 'programmer not responding' followed by ten messages about attempting to sync, and the last part of the verbose message is the familiar 'Problem uploading to board. See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.'
Before I bin them, are there any methodical steps I can follow (sw and/or hw) in an attempt to salvage it in some minimal form please?
And a general question: is there any tool that would take as input the voltages on each of the 28 pins and suggest a likely cause of the failure?
Terrypin:
Presumably through carelessness while breadboarding I now have two 328s which won't upload any sketch. The green power LED and the yellow D13 LED are on. Both give the same error, 'programmer not responding' followed by ten messages about attempting to sync, and the last part of the verbose message is the familiar 'Problem uploading to board. See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.'
Before I bin them, are there any methodical steps I can follow (sw and/or hw) in an attempt to salvage it in some minimal form please?
And a general question: is there any tool that would take as input the voltages on each of the 28 pins and suggest a likely cause of the failure?
This can happen if -
You connect any higher voltage to the chip.
You connect the 5V to any other pin that it is not supposed to be connected.
You change its fuse bytes.
There could be also an other problem, that is for the Arduino IDE. Please tell which programmer you are using and how did you connect the chip to that. And tell us if the two Atmegas were working properly in past.
Yes, I probably did connect > 5V to one of the pins. The chip was working fine previously. The programmer is set as usual to AVRISP mkII, if that's what you mean? The chip gives the same error whether on my UNO R3 or independently witn 5V supply.
So my question is whether there are any practical steps I can take to recover some functionality. I tried Tools > Burn Bootloader but that didn't work.
Tools -> Burn bootloader will only ever do anything if you have an external ISP programmer wired to the Arduino in question.
Tools -> programmer will only ever do anything if you have an external ISP programmer wired to the Arduino in question and do either tools -> burn bootloader or sketch -> upload using programmer (note: this applies to official boards; AVR devices that do not use a bootloader behave differently, this is beyond the scope of this thread)
But the error you describe, as well as your admission of having connected >5v to one of the pins, indicates that you have damaged the '328p (also, the pin 13 LED stuck on is a common symptom of a burned out uno board, too - the opamp that buffers pin13 is easy to burn out, and this is the symptom). Discard the damaged board and buy a new one - uno clones are like $8 tops... trying to revive a board that you are almost certain is broken is a waste of time. Consider minimum wage and the replacement cost
I just hate throwing stuff away and was hoping the chip (which is mounted independently of my UNO) would still work from an undamaged pin if I could hack it in some way.
