extruder: Add a SET_EXTRUDER_ROTATION_DISTANCE command

Support altering the extruder distance using the higher-level
rotation_distance.  This is in preparation for removal of the
SET_EXTRUDER_STEP_DISTANCE command.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

docs/G-Codes.md

@@ -300,14 +300,23 @@ extruders this command is used to change the active extruder.
 parameters. If EXTRUDER is not specified, it defaults to the active
 extruder.
 
+#### SET_EXTRUDER_ROTATION_DISTANCE
+`SET_EXTRUDER_ROTATION_DISTANCE EXTRUDER=<config_name>
+[DISTANCE=<distance>]`: Set a new value for the provided extruder's
+"rotation distance". Value is not retained on Klipper reset. Use with
+caution as small changes can result in excessive pressure between
+extruder and hot end. Do proper calibration with filament before use.
+If 'DISTANCE' value is not included command will return current
+rotation distance.
+
 #### SET_EXTRUDER_STEP_DISTANCE
-`SET_EXTRUDER_STEP_DISTANCE [EXTRUDER=<config_name>]
+`SET_EXTRUDER_STEP_DISTANCE EXTRUDER=<config_name>
 [DISTANCE=<distance>]`: Set a new value for the provided extruder's
 "step distance". The "step distance" is
 `rotation_distance/(full_steps_per_rotation*microsteps)`. Value is not
-retained on Klipper reset. Use with caution, small changes can result
+retained on Klipper reset. Use with caution as small changes can
-in excessive pressure between extruder and hot end. Do proper
+result in excessive pressure between extruder and hot end. Do proper
-calibration steps with filament before use. If 'DISTANCE' value is not
+calibration with filament before use. If 'DISTANCE' value is not
 included command will return current step distance.
 
 #### SYNC_STEPPER_TO_EXTRUDER

klippy/extras/endstop_phase.py

@@ -54,7 +54,8 @@ class EndstopPhase:
         self.name = config.get_name().split()[1]
         # Obtain step_distance and microsteps from stepper config section
         sconfig = config.getsection(self.name)
-        self.step_dist = stepper.parse_step_distance(sconfig)
+        rotation_dist, steps_per_rotation = stepper.parse_step_distance(sconfig)
+        self.step_dist = rotation_dist / steps_per_rotation
         self.phases = sconfig.getint("microsteps", note_valid=False) * 4
         self.phase_calc = PhaseCalc(self.printer, self.name, self.phases)
         # Register event handlers

klippy/extras/tmc.py

@@ -520,8 +520,9 @@ def TMCStealthchopHelper(config, mcu_tmc, tmc_freq):
     velocity = config.getfloat('stealthchop_threshold', 0., minval=0.)
     if velocity:
         stepper_name = " ".join(config.get_name().split()[1:])
-        stepper_config = config.getsection(stepper_name)
+        sconfig = config.getsection(stepper_name)
-        step_dist = stepper.parse_step_distance(stepper_config)
+        rotation_dist, steps_per_rotation = stepper.parse_step_distance(sconfig)
+        step_dist = rotation_dist / steps_per_rotation
         step_dist_256 = step_dist / (1 << fields.get_field("mres"))
         threshold = int(tmc_freq * step_dist_256 / velocity + .5)
         fields.set_field("tpwmthrs", max(0, min(0xfffff, threshold)))

klippy/kinematics/extruder.py

@@ -28,6 +28,9 @@ class ExtruderStepper:
         gcode.register_mux_command("SET_PRESSURE_ADVANCE", "EXTRUDER",
                                    self.name, self.cmd_SET_PRESSURE_ADVANCE,
                                    desc=self.cmd_SET_PRESSURE_ADVANCE_help)
+        gcode.register_mux_command("SET_EXTRUDER_ROTATION_DISTANCE", "EXTRUDER",
+                                   self.name, self.cmd_SET_E_ROTATION_DISTANCE,
+                                   desc=self.cmd_SET_E_ROTATION_DISTANCE_help)
         gcode.register_mux_command("SET_EXTRUDER_STEP_DISTANCE", "EXTRUDER",
                                    self.name, self.cmd_SET_E_STEP_DISTANCE,
                                    desc=self.cmd_SET_E_STEP_DISTANCE_help)
@@ -86,19 +89,29 @@ class ExtruderStepper:
                % (pressure_advance, smooth_time))
         self.printer.set_rollover_info(self.name, "%s: %s" % (self.name, msg))
         gcmd.respond_info(msg, log=False)
+    cmd_SET_E_ROTATION_DISTANCE_help = "Set extruder rotation distance"
+    def cmd_SET_E_ROTATION_DISTANCE(self, gcmd):
+        rotation_dist = gcmd.get_float('DISTANCE', None, above=0.)
+        if rotation_dist is not None:
+            toolhead = self.printer.lookup_object('toolhead')
+            toolhead.flush_step_generation()
+            self.stepper.set_rotation_distance(rotation_dist)
+        else:
+            rotation_dist, spr = self.stepper.get_rotation_distance()
+        gcmd.respond_info("Extruder '%s' rotation distance set to %0.6f"
+                          % (self.name, rotation_dist))
     cmd_SET_E_STEP_DISTANCE_help = "Set extruder step distance"
     def cmd_SET_E_STEP_DISTANCE(self, gcmd):
-        toolhead = self.printer.lookup_object('toolhead')
+        step_dist = gcmd.get_float('DISTANCE', None, above=0.)
-        dist = gcmd.get_float('DISTANCE', None, above=0.)
+        if step_dist is not None:
-        if dist is None:
+            toolhead = self.printer.lookup_object('toolhead')
+            toolhead.flush_step_generation()
+            rd, steps_per_rotation = self.stepper.get_rotation_distance()
+            self.stepper.set_rotation_distance(step_dist * steps_per_rotation)
+        else:
             step_dist = self.stepper.get_step_dist()
-            gcmd.respond_info("Extruder '%s' step distance is %0.6f"
-                              % (self.name, step_dist))
-            return
-        toolhead.flush_step_generation()
-        self.stepper.set_step_dist(dist)
         gcmd.respond_info("Extruder '%s' step distance set to %0.6f"
-                          % (self.name, dist))
+                          % (self.name, step_dist))
     cmd_SYNC_STEPPER_TO_EXTRUDER_help = "Set extruder stepper"
     def cmd_SYNC_STEPPER_TO_EXTRUDER(self, gcmd):
         ename = gcmd.get('EXTRUDER')

klippy/stepper.py

@@ -18,12 +18,15 @@ MIN_BOTH_EDGE_DURATION = 0.000000200
 
 # Interface to low-level mcu and chelper code
 class MCU_stepper:
-    def __init__(self, name, step_pin_params, dir_pin_params, step_dist,
+    def __init__(self, name, step_pin_params, dir_pin_params,
+                 rotation_dist, steps_per_rotation,
                  step_pulse_duration=None, units_in_radians=False):
         self._name = name
-        self._step_dist = step_dist
+        self._rotation_dist = rotation_dist
+        self._steps_per_rotation = steps_per_rotation
         self._step_pulse_duration = step_pulse_duration
         self._units_in_radians = units_in_radians
+        self._step_dist = rotation_dist / steps_per_rotation
         self._mcu = step_pin_params['chip']
         self._oid = oid = self._mcu.create_oid()
         self._mcu.register_config_callback(self._build_config)
@@ -103,9 +106,12 @@ class MCU_stepper:
         return self._oid
     def get_step_dist(self):
         return self._step_dist
-    def set_step_dist(self, dist):
+    def get_rotation_distance(self):
+        return self._rotation_dist, self._steps_per_rotation
+    def set_rotation_distance(self, rotation_dist):
         mcu_pos = self.get_mcu_position()
-        self._step_dist = dist
+        self._rotation_dist = rotation_dist
+        self._step_dist = rotation_dist / self._steps_per_rotation
         self.set_stepper_kinematics(self._stepper_kinematics)
         self._set_mcu_position(mcu_pos)
     def is_dir_inverted(self):
@@ -222,10 +228,12 @@ def PrinterStepper(config, units_in_radians=False):
     step_pin_params = ppins.lookup_pin(step_pin, can_invert=True)
     dir_pin = config.get('dir_pin')
     dir_pin_params = ppins.lookup_pin(dir_pin, can_invert=True)
-    step_dist = parse_step_distance(config, units_in_radians, True)
+    rotation_dist, steps_per_rotation = parse_step_distance(
+        config, units_in_radians, True)
     step_pulse_duration = config.getfloat('step_pulse_duration', None,
                                           minval=0., maxval=.001)
-    mcu_stepper = MCU_stepper(name, step_pin_params, dir_pin_params, step_dist,
+    mcu_stepper = MCU_stepper(name, step_pin_params, dir_pin_params,
+                              rotation_dist, steps_per_rotation,
                               step_pulse_duration, units_in_radians)
     # Register with helper modules
     for mname in ['stepper_enable', 'force_move', 'motion_report']:
@@ -263,7 +271,7 @@ def parse_step_distance(config, units_in_radians=None, note_valid=False):
         raise config.error("full_steps_per_rotation invalid in section '%s'"
                            % (config.get_name(),))
     gearing = parse_gear_ratio(config, note_valid)
-    return rotation_dist / (full_steps * microsteps * gearing)
+    return rotation_dist, full_steps * microsteps * gearing
 
 
 ######################################################################