Closed Loop: jolt when switching mode

[T3P3]

When switching into closed loop mode, read the microstep position and set the motor currents to be the same phase, to avoid a jolt.

Now there is no jolt at the start, but there is a jolt at the end, at least when the encoder is working in reverse polarity

[dc42]

There is a more severe jolt when switching from closed to open loop mode after doing some movement in closed loop mode.

[dc42]

Fixed this apart from the jolt when switching form closed loop back to open loop after doing movement. To avoid the jolt we could:

• Disable the driver
• Switch the driver out of XDIRECT mode
• Send step pulses to the driver until the microstep counter is at the correct phase position
• Re-enable the driver Alternatively, we could use XDIRECT mode even for open loop operation and never generate step/dir signals, then we would never need to sync the microstep counter with the phase position.