Improved dc motor slow down and stop.

motor.c

@@ -454,20 +454,26 @@ void dda_start(DDA *dda) {
         uint8_t queue_elements = queue_current_size();
         if(dda->dc_motor_speed == 0 )
         { 
-			// turn off motor now for jump move
-			if (dda->waitfor == 0)
-				desired_speed = 0;
-			else
-				stop_dc_motor();
+			// turn off motor for jump move after current one stitch
+			if (desired_speed > 0)
+            {
+				stop_dc_motor(1);
+                dda->waitfor = 1;
+            }
 		}
 		else
 		{
 			// slow down on almost empty buffer
 			if(queue_elements < 4)
 			{
-				desired_speed = dda->dc_motor_speed / 2;
-				if(desired_speed < MIN_MOTOR_SPEED)
-					desired_speed = MIN_MOTOR_SPEED;
+                if(queue_elements < 2)
+                    desired_speed = MIN_MOTOR_SPEED;
+                else
+                {
+                    desired_speed = dda->dc_motor_speed / 2;
+                    if(desired_speed < MIN_MOTOR_SPEED)
+                        desired_speed = MIN_MOTOR_SPEED;
+                }
 			}
 			else // just use planned speed value from dda
 				desired_speed = dda->dc_motor_speed;
@@ -481,10 +487,9 @@ void dda_start(DDA *dda) {
             return;
         #endif
         
-        // buffer is empty, this is probably last move
+        // buffer is empty, this is probably last move, stop now
         if(queue_elements == 0) 
-            desired_speed = 0;
-
+            stop_dc_motor(0);
         
   if (DEBUG_DDA && (debug_flags & DEBUG_DDA))
     #ifdef STEPS_PER_M_Z

queue.c

@@ -111,11 +111,11 @@ void enqueue_home(TARGET const *t, uint8_t endstop_check, uint8_t endstop_stop_c
   new_movebuffer->endstop_check = endstop_check;
   new_movebuffer->endstop_stop_cond = endstop_stop_cond;
   #ifdef TRIGGERED_MOVEMENT
-  // this dda is started by interrupt
+  // this dda is started by external interrupt
   if(endstop_stop_cond & 0xf0)
-  {
      new_movebuffer->waitfor = 1;
-  }
+  else
+     new_movebuffer->waitfor = 0;
   #endif
   dda_create(new_movebuffer, t);
 

sensors_control.c

@@ -100,12 +100,21 @@ void set_dc_motor_speed_margin(int16_t value)
 		margin_max_speed = MAX_MOTOR_SPEED;
 }
 
-/// activates stop of the the motor on needle interrupt
-void stop_dc_motor()
+/// activates stop of the the motor on needle downwards interrupt
+/// mode 0 - stop on first interrupt, any other value - stop on next one interrupt
+void stop_dc_motor(uint8_t mode)
 {
-	if(desired_speed == 0) return;
-	desired_speed = MIN_MOTOR_SPEED;
-	stop_motor_flag = 1;
+    if (stop_motor_flag || desired_speed == 0) return;
+    if (mode)
+    {
+        desired_speed = MIN_MOTOR_SPEED;
+        stop_motor_flag = 2;
+    }
+    else
+    {
+        desired_speed = MIN_MOTOR_SPEED/2;
+        stop_motor_flag = 1;
+    }
 }
 
 /// PI control update procedure
@@ -164,26 +173,37 @@ ISR(INT1_vect)
 		if(last_direction)
 			return;
 		last_direction = 1;
-		if(stop_motor_flag)
-		{
-			desired_speed = 0;
-			stop_motor_flag = 0;
-		}
-		//serial_writestr_P(PSTR("int1 up\n"));
-		if(mb_tail_dda && !mb_tail_dda->live)
+        if(stop_motor_flag == 2)
+        {
+            --stop_motor_flag;
+            desired_speed = MIN_MOTOR_SPEED/2;
+        }
+		if(mb_tail_dda && !mb_tail_dda->live && !stop_motor_flag)
 		{
 			mb_tail_dda->waitfor = 0;
 			dda_start(mb_tail_dda);
 			sei();
 		}
+        //serial_writestr_P(PSTR("int1 up\n"));
 	}
 	else // needle goes downwards
 	{
 		if(!last_direction)
 			return;
-		//serial_writestr_P(PSTR("int1 down\n"));
 		last_direction = 0;
 		//TODO: stop any movement currently in progress
+		if(stop_motor_flag == 1)
+		{
+			desired_speed = 0;
+			stop_motor_flag = 0;
+            if(mb_tail_dda && !mb_tail_dda->live)
+            {
+                mb_tail_dda->waitfor = 0;
+                dda_start(mb_tail_dda);
+                sei();
+            }
+		}
+        //serial_writestr_P(PSTR("int1 down\n"));
 	}
 }
 

sensors_control.h

@@ -12,7 +12,7 @@
 
 extern int16_t desired_speed;
 extern int16_t margin_max_speed;
-void stop_dc_motor();
+void stop_dc_motor(uint8_t);
 
 #ifdef __cplusplus
 extern "C" {