I have an ATtiny841, which I wanted to clock with the internal ultra low power oscillator @32kHz. I am using AtmelStudio 7 with AVR Dragon.
So I've set up the fuses properly for the clock source. With the new clock, I even had to lower the ISP Clock, so that it is below 32kHz/4, to verify the results. So it seems like the setting of the clock succeeded.
Then I wanted to load and debug my code, so I enabled debugWire as prompted by AS7. After power cycling the ATtiny, though, the debugger could not connect to the device. And ever since, I cannot access it neither with debugWire, nor with ISP.
My assumption is that debugWire got enabled (DWEN fuse is set), but it does not work with such a low clock speed. (I've found in the specs of the ATtiny841, that "clock frequencies below 100kHz may cause communication problems", of course only after I was already stuck.) As I cannot connect to the debugWire interface, I cannot disable it, and with enabled debugWire, I cannot use ISP either to clear the DWEN fuse.
So the question is simple: Is there anything I can do?
(PS: I've found and read through lot's of questions on disabling debugWire, but none of what I've found was related to slow clock speed.)