Extruder: Add g-code to set extruder step_distance (#2598)

Signed off by: David Smith <[email protected]>

docs/G-Codes.md

@@ -162,6 +162,12 @@ The following standard commands are supported:
   [SMOOTH_TIME=<pressure_advance_smooth_time>]`: Set pressure advance
   parameters. If EXTRUDER is not specified, it defaults to the active
   extruder.
+- `SET_EXTRUDER_STEP_DISTANCE [EXTRUDER=<config_name>] [DISTANCE=<distance>]`:
+  Set a new value for the provided extruder's step_distance. Value is
+  not retained on Klipper reset. Use with caution, small changes can
+  result in excessive pressure between extruder and hot end. Do proper
+  calibration steps with filament before use. If 'DISTANCE' value is
+  not included command will return current step distance.
 - `SET_STEPPER_ENABLE STEPPER=<config_name> ENABLE=[0|1]`: Enable or
   disable only the given stepper. This is a diagnostic and debugging
   tool and must be used with care. Disabling an axis motor does not

klippy/kinematics/extruder.py

@@ -72,6 +72,9 @@ def __init__(self, config, extruder_num):
         gcode.register_mux_command("ACTIVATE_EXTRUDER", "EXTRUDER",
                                    self.name, self.cmd_ACTIVATE_EXTRUDER,
                                    desc=self.cmd_ACTIVATE_EXTRUDER_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)
     def update_move_time(self, flush_time):
         self.trapq_free_moves(self.trapq, flush_time)
     def _set_pressure_advance(self, pressure_advance, smooth_time):
@@ -185,6 +188,20 @@ def cmd_SET_PRESSURE_ADVANCE(self, params):
                    pressure_advance, smooth_time))
         self.printer.set_rollover_info(self.name, "%s: %s" % (self.name, msg))
         gcode.respond_info(msg, log=False)
+    cmd_SET_E_STEP_DISTANCE_help = "Set extruder step distance"
+    def cmd_SET_E_STEP_DISTANCE(self, params):
+        gcode = self.printer.lookup_object('gcode')
+        toolhead = self.printer.lookup_object('toolhead')
+        if 'DISTANCE' not in params:
+            step_dist = self.stepper.get_step_dist()
+            gcode.respond_info("%s E step distance: %f" % (self.name, step_dist))
+            return
+        dist = gcode.get_float('DISTANCE', params, 0.)
+        toolhead.flush_step_generation()
+        self.stepper.set_step_dist(self.sk_extruder, dist)
+        step_dist = self.stepper.get_step_dist()
+        gcode.respond_info("%s E step distance set: %f" %
+                                                (self.name, step_dist))
     cmd_ACTIVATE_EXTRUDER_help = "Change the active extruder"
     def cmd_ACTIVATE_EXTRUDER(self, params):
         gcode = self.printer.lookup_object('gcode')

klippy/stepper.py

@@ -94,6 +94,10 @@ def get_oid(self):
         return self._oid
     def get_step_dist(self):
         return self._step_dist
+    def set_step_dist(self, sk, dist):
+        self._step_dist = dist
+        self.set_stepper_kinematics(sk)
+        logging.info("%s manually set to =%.6f", (self._name, dist))
     def is_dir_inverted(self):
         return self._invert_dir
     def calc_position_from_coord(self, coord):