Increase the extra length allowed for homing, to allow the machine to home properly when the homing switch is far from the
bed.
personal configuration
Use the software PWM for fan control to not generate annoying sounds. Allow increasing software PWM frequency.
Control the fan when it's supposed to be, not when the g-codes are received.
Fix compilation on Arduino 1.0.
Fix stepper control problems with 20MHz CPU frequency.
Make M502 command restore all settings to default, not just half of them.
Don't sleep needlessly and delay commands from serial port.
update personal configuration