Added modified lwip files that were missed from last checkin
Fixed incorrect JSON format in response to the rr_files command when no
files were found
Enabled hardware debounce filter on cooling fan RPM pin to get a correct
and stable readout
Fixed bug that caused the cooling fan PWM frequency to be 165kHz. It is
now 25kHz.
Fan RPM is now included in the web interface status response (thanks
zpl).
Many more error messages are now reported to the web interface as well
as the USB interface.
Interrupt-driven network timer task to better cope with slow SD card
writes (thanks zpl)
Module SamNonDuePin is now used for all digital and PWM pin I/O.