* Adding Z hold to test certain acme configurations.

v2/src/Motherboard/Steppers.cc

@@ -168,13 +168,19 @@ const Point getPosition() {
 	return Point(axes[0].position,axes[1].position,axes[2].position);
 }
 
+bool holdZ = false;
+
+void setHoldZ(bool holdZ_in) {
+	holdZ = holdZ_in;
+}
+
 void setTarget(const Point& target, int32_t dda_interval) {
 	int32_t max_delta = 0;
 	for (int i = 0; i < AXIS_COUNT; i++) {
 		axes[i].setTarget(target[i]);
 		const int32_t delta = axes[i].delta;
 		// Only shut z axis on inactivity
-		if (i == 2) axes[i].enableStepper(delta != 0);
+		if (i == 2 && !holdZ) axes[i].enableStepper(delta != 0);
 		else if (delta != 0) axes[i].enableStepper(true);
 		if (delta > max_delta) {
 			max_delta = delta;

v2/src/Motherboard/Steppers.hh

@@ -50,6 +50,8 @@ void definePosition(const Point& position);
 bool doInterrupt();
 /// Get current position
 const Point getPosition();
+/// Turn on in-build Z hold.  Defaults to off.
+void setHoldZ(bool holdZ);
 };
 
 #endif // STEPPERS_HH_

v2/src/Motherboard/boards/rrmbv22/Motherboard.cc

@@ -58,6 +58,8 @@ void Motherboard::reset() {
 	getPSU().init();
 	getPSU().turnOn(true);
 	// Init steppers
+	// NB: for now, we are turning on Z hold for these boards!
+	steppers::setHoldZ(true);
 	for (int i = 0; i < STEPPER_COUNT; i++) {
 		stepper[i].init(i);
 	}