Feature Request: Consider adding automatic DCC phase reversal

[peteGSX]

More feedback from Alex in Discord which is probably a great idea:

Is your feature request related to a problem? Please describe.

It's worth considering having the DCC phase automatically reversing when rotating 180 degrees to make it easier.

Describe the solution you'd like

When a turntable rotates beyond 180 degrees, the DCC phase should automatically invert, and return to normal phase once rotating back to within the first 180 degrees.

Describe alternatives you've considered

N/A

Additional context

Consideration during the remainder of the conversation is to have auto reversal as the default, but still enabling use of the Turn_PInvert command if users prefer, and an option to not invert at all which would be applicable in scenarios such as traversers that don't actually rotate.

[peteGSX]

Current thinking on this:

• Align the home sensor with the main layout connection track (or track of user's choosing).
• Auto polarity reversal will happen at 45 degrees and 225 degrees.
• Conductor level users just use that and move on, noting they shouldn't have layout connections at 45/225.

For the Tinkerers and Engineers:

• We already have the capability to let users define polarity reversal at each position with the Turn_PInvert command if that behaviour is preferred.
• We can also add an override option for the auto phase inversion degrees, so you can specify 30/210 or whatever suits to move from the default 45/225.

The other item thinking forward and related to the Traverser feature request is to allow an override to disable phase switching, although this is probably easiest by choosing a flag as AUTO or MANUAL for phase switching, and the traversers can simply never use the Turn_PInvert command with the MANUAL option enabled. This also will allow the phase inversion to work with turntables that rotate, but not the full 360 degrees, as they will still require phase inversion.

[peteGSX]

Unit testing:

• config.h with PHASE_SWITCHING AUTO and PHASE_SWITCH_ANGLE 45 results in phase automatically switching at the step count defined by fullStepCount / 360 PHASE_SWITCH_ANGLE, and automatically reverts at the step count defined by fullStepCount / 360 (PHASE_SWITCH_ANGLE + 180).
• Commands sent with PHASE_SWITCHING AUTO adhere to the phase as per the step counts above, and override the phase switching activity sent with the command.
• config.h with PHASE_SWITCHING MANUAL ignores all automatic phase switching, and phase switching only occurs when sent as the activity command.
• Setting PHASE_SWITCH_ANGLE to any value that results in the revert angle being equal to or greater than 360 degrees reports an error, and uses the default of 45 degrees.
• If Turntable-EX has not been calibrated, the phase switching steps should not be defined at startup, but should be defined at the end of the calibration sequence.

[peteGSX]

Will also include https://github.com/DCC-EX/Turntable-EX/issues/48.

[peteGSX]

All unit tests passed.