If the watchdog trips; it is not then possible to program the baord without putting it into DFU mode.
a/ enable watchdog
b/ watchdog trips
c/ program operation will fail with error code 74
d/ you will need to reset the board with the onboard button to put it in DFU mode
I'm fairly sure this happens when the watchdog is enabled also - so developing any project that uses the watchdog becomes very time consuming as program downloads repeatedly fail.
My current workaround is disabling the watchdog during application development then enabling it after most of the code development - not great.
I think this used to be a problem with the atmega nano but they fixed the bootloader to reset the watchdog flags following a reboot.
If the watchdog trips; it is not then possible to program the baord without putting it into DFU mode.
a/ enable watchdog
b/ watchdog trips
c/ program operation will fail with error code 74
d/ you will need to reset the board with the onboard button to put it in DFU mode
I'm fairly sure this happens when the watchdog is enabled also - so developing any project that uses the watchdog becomes very time consuming as program downloads repeatedly fail.
My current workaround is disabling the watchdog during application development then enabling it after most of the code development - not great.
I think this used to be a problem with the atmega nano but they fixed the bootloader to reset the watchdog flags following a reboot.