Merge branch 'master' into servo_template

docs/Config_Changes.md

@@ -8,6 +8,15 @@ All dates in this document are approximate.
 
 ## Changes
 
+20230826: If `safe_distance` is set or calculated to be 0 in `[dual_carriage]`,
+the carriages proximity checks will be disabled as per documentation. A user
+may wish to configure `safe_distance` explicitly to prevent accidental crashes
+of the carriages with each other. Additionally, the homing order of the primary
+and the dual carriage is changed in some configurations (certain configurations
+when both carriages home in the same direction, see
+[[dual_carriage] configuration reference](./Config_Reference.md#dual_carriage)
+for more details).
+
 20230820: The heater `smooth_time` now defaults to not perform any
 additional temperature smoothing. To return to the previous behavior
 of one second smoothing, set `smooth_time: 1.0` in the heater config

docs/Config_Reference.md

@@ -2183,6 +2183,14 @@ in this section (CARRIAGE=0 will return activation to the primary carriage).
 Dual carriage support is typically combined with extra extruders - the
 SET_DUAL_CARRIAGE command is often called at the same time as the
 ACTIVATE_EXTRUDER command. Be sure to park the carriages during deactivation.
+Note that during G28 homing, typically the primary carriage is homed first
+followed by the carriage defined in the `[dual_carriage]` config section.
+However, the `[dual_carriage]` carriage will be homed first if both carriages
+home in a positive direction and the [dual_carriage] carriage has a
+`position_endstop` greater than the primary carriage, or if both carriages home
+in a negative direction and the `[dual_carriage]` carriage has a
+`position_endstop` less than the primary carriage.
+
 Additionally, one could use "SET_DUAL_CARRIAGE CARRIAGE=1 MODE=COPY" or
 "SET_DUAL_CARRIAGE CARRIAGE=1 MODE=MIRROR" commands to activate either copying
 or mirroring mode of the dual carriage, in which case it will follow the

docs/RPi_microcontroller.md

@@ -203,7 +203,7 @@ channels need to be enabled you can use `pwm-2chan`:
 # Enable pwmchip sysfs interface
 dtoverlay=pwm-2chan,pin=12,func=4,pin2=13,func2=4
 ```
-This example additionaly enables PWM1 and routes it to gpio13.
+This example additionally enables PWM1 and routes it to gpio13.
 
 The overlay does not expose the pwm line on sysfs on boot and needs to
 be exported by echo'ing the number of the pwm channel to

klippy/kinematics/idex_modes.py

@@ -65,7 +65,13 @@ def toggle_active_dc_rail(self, index, override_rail=False):
         kin.update_limits(self.axis, target_dc.get_rail().get_range())
     def home(self, homing_state):
         kin = self.printer.lookup_object('toolhead').get_kinematics()
-        for i, dc_rail in enumerate(self.dc):
+        enumerated_dcs = list(enumerate(self.dc))
+        if (self.get_dc_order(0, 1) > 0) != \
+                self.dc[0].get_rail().get_homing_info().positive_dir:
+            # The second carriage must home first, because the carriages home in
+            # the same direction and the first carriage homes on the second one
+            enumerated_dcs.reverse()
+        for i, dc_rail in enumerated_dcs:
             self.toggle_active_dc_rail(i, override_rail=True)
             kin.home_axis(homing_state, self.axis, dc_rail.get_rail())
         # Restore the original rails ordering
@@ -78,17 +84,23 @@ def get_kin_range(self, toolhead, mode):
         axes_pos = [dc.get_axis_position(pos) for dc in self.dc]
         dc0_rail = self.dc[0].get_rail()
         dc1_rail = self.dc[1].get_rail()
-        range_min = dc0_rail.position_min
-        range_max = dc0_rail.position_max
+        if mode != PRIMARY or self.dc[0].is_active():
+            range_min = dc0_rail.position_min
+            range_max = dc0_rail.position_max
+        else:
+            range_min = dc1_rail.position_min
+            range_max = dc1_rail.position_max
         safe_dist = self.safe_dist
+        if not safe_dist:
+            return (range_min, range_max)
 
         if mode == COPY:
             range_min = max(range_min,
                             axes_pos[0] - axes_pos[1] + dc1_rail.position_min)
             range_max = min(range_max,
                             axes_pos[0] - axes_pos[1] + dc1_rail.position_max)
         elif mode == MIRROR:
-            if dc0_rail.get_homing_info().positive_dir:
+            if self.get_dc_order(0, 1) > 0:
                 range_min = max(range_min,
                                 0.5 * (sum(axes_pos) + safe_dist))
                 range_max = min(range_max,
@@ -102,14 +114,39 @@ def get_kin_range(self, toolhead, mode):
             # mode == PRIMARY
             active_idx = 1 if self.dc[1].is_active() else 0
             inactive_idx = 1 - active_idx
-            if active_idx:
-                range_min = dc1_rail.position_min
-                range_max = dc1_rail.position_max
-            if self.dc[active_idx].get_rail().get_homing_info().positive_dir:
+            if self.get_dc_order(active_idx, inactive_idx) > 0:
                 range_min = max(range_min, axes_pos[inactive_idx] + safe_dist)
             else:
                 range_max = min(range_max, axes_pos[inactive_idx] - safe_dist)
+        if range_min > range_max:
+            # During multi-MCU homing it is possible that the carriage
+            # position will end up below position_min or above position_max
+            # if position_endstop is too close to the rail motion ends due
+            # to inherent latencies of the data transmission between MCUs.
+            # This can result in an invalid range_min > range_max range
+            # in certain modes, which may confuse the kinematics code.
+            # So, return an empty range instead, which will correctly
+            # block the carriage motion until a different mode is selected
+            # which actually permits carriage motion.
+            return (range_min, range_min)
         return (range_min, range_max)
+    def get_dc_order(self, first, second):
+        if first == second:
+            return 0
+        # Check the relative order of the first and second carriages and
+        # return -1 if the first carriage position is always smaller
+        # than the second one and 1 otherwise
+        first_rail = self.dc[first].get_rail()
+        second_rail = self.dc[second].get_rail()
+        first_homing_info = first_rail.get_homing_info()
+        second_homing_info = second_rail.get_homing_info()
+        if first_homing_info.positive_dir != second_homing_info.positive_dir:
+            # Carriages home away from each other
+            return 1 if first_homing_info.positive_dir else -1
+        # Carriages home in the same direction
+        if first_rail.position_endstop > second_rail.position_endstop:
+            return 1
+        return -1
     def activate_dc_mode(self, index, mode):
         toolhead = self.printer.lookup_object('toolhead')
         toolhead.flush_step_generation()