MAYBE this helps someboy.
I get more from this forum than I can give to the community, this is becasue most here know much more about the different ATMELs than I do.
anyway, maybe I can give here something back to the community.
I had this „Failed to enter programming mode. ispEnterProgMode: Error status received: Got 0xc0, expected 0x00“ issue, which is widely discussed already in this forum with an endless number of reasons and solutions
I did try almost all of the possible reasons/solutions; but my case was another one, can say „home made“.
I did add a diode in the VCC path to prevent energy flow back to my power supply; I need to keep the controller running for a while when mains switched off.
BUT…my programming interface was connected before this diode. Means: programmer did think I have 3.3V but on uC I had 3.3V - Vfdiode (about 2,7V).
For about 2 weeks this solution did work well and I could develop my software. Then unluckily after a Windows BlueScreen I could not program the uC any more, the 2nd board also not.
Sure the Windows BlueScreen let me think I did kill a driver in AtmelStudio or such issue.
USB Power on my MAcBook air is also a bit weak..this I also did double check…and so on.
Then I did change the Dragon Board to the newest ICE programmer and of course did study all the different entries here in the forum about this „Got 0xc0, expected 0x00“ issue“
Funny thing was with ICE I could do Debug Wire programming at 1 board but not at the 2nd
ISP did bot work on both.
After I shortcut my diode..all works well again
Maybe some other also have such an issue and my case prevent them to search in the dark forever.
It is strange how the brain works: the error message on AVRStudio gives a hint already: "please check if VCC is correct and cabels correct" YES YES YES; I did swtich on the power blar blar blar.
But finally it was eactly this "YES clear" thing.