fix(api): we should always call ot3controller.gripper_home_jaw() to home G axis (#12376)

Author: ahiuchingau

api/src/opentrons/config/defaults_ot3.py

@@ -71,7 +71,6 @@
 DEFAULT_RIGHT_MOUNT_OFFSET: Final[Offset] = (40.5, -60.5, 255.675)
 DEFAULT_GRIPPER_MOUNT_OFFSET: Final[Offset] = (84.55, -12.75, 93.85)
 DEFAULT_Z_RETRACT_DISTANCE: Final = 2
-DEFAULT_GRIPPER_JAW_HOME_DUTY_CYCLE: Final = 25
 DEFAULT_SAFE_HOME_DISTANCE: Final = 5
 
 DEFAULT_MAX_SPEEDS: Final[ByGantryLoad[Dict[OT3AxisKind, float]]] = ByGantryLoad(
@@ -380,9 +379,6 @@ def build_with_defaults(robot_settings: Dict[str, Any]) -> OT3Config:
         z_retract_distance=robot_settings.get(
             "z_retract_distance", DEFAULT_Z_RETRACT_DISTANCE
         ),
-        grip_jaw_home_duty_cycle=robot_settings.get(
-            "grip_jaw_home_duty_cycle", DEFAULT_GRIPPER_JAW_HOME_DUTY_CYCLE
-        ),
         safe_home_distance=robot_settings.get(
             "safe_home_distance", DEFAULT_SAFE_HOME_DISTANCE
         ),

api/src/opentrons/config/types.py

@@ -175,7 +175,6 @@ class OT3Config:
     motion_settings: OT3MotionSettings
     current_settings: OT3CurrentSettings
     z_retract_distance: float
-    grip_jaw_home_duty_cycle: float
     safe_home_distance: float
     deck_transform: OT3Transform
     carriage_offset: Offset

api/src/opentrons/hardware_control/backends/ot3controller.py

@@ -608,6 +608,9 @@ async def home(self, axes: Sequence[OT3Axis]) -> OT3AxisMap[float]:
             A dictionary containing the new positions of each axis
         """
         checked_axes = [axis for axis in axes if self._axis_is_present(axis)]
+        assert (
+            OT3Axis.G not in checked_axes
+        ), "Please home G axis using gripper_home_jaw()"
         if not checked_axes:
             return {}
 
@@ -621,8 +624,6 @@ async def home(self, axes: Sequence[OT3Axis]) -> OT3AxisMap[float]:
             if runner
         ]
         positions = await asyncio.gather(*coros)
-        if OT3Axis.G in checked_axes:
-            await self.gripper_home_jaw(self._configuration.grip_jaw_home_duty_cycle)
         if OT3Axis.Q in checked_axes:
             await self.tip_action(
                 [OT3Axis.Q],

api/src/opentrons/hardware_control/ot3api.py

@@ -728,12 +728,16 @@ async def home_gripper_jaw(self) -> None:
         """
         Home the jaw of the gripper.
         """
-        gripper = self._gripper_handler.get_gripper()
-        dc = self._gripper_handler.get_duty_cycle_by_grip_force(
-            gripper.default_home_force
-        )
-        await self._ungrip(duty_cycle=dc)
-        gripper.state = GripperJawState.HOMED_READY
+        try:
+            gripper = self._gripper_handler.get_gripper()
+            self._log.info("Homing gripper jaw.")
+            dc = self._gripper_handler.get_duty_cycle_by_grip_force(
+                gripper.default_home_force
+            )
+            await self._ungrip(duty_cycle=dc)
+            gripper.state = GripperJawState.HOMED_READY
+        except GripperNotAttachedError:
+            pass
 
     async def home_plunger(self, mount: Union[top_types.Mount, OT3Mount]) -> None:
         """
@@ -1191,8 +1195,9 @@ async def _home(self, axes: Sequence[OT3Axis]) -> None:
         async with self._motion_lock:
             for axis in axes:
                 try:
-                    # let backend handle homing gripper jaw and pipette plunger
-                    if axis in [OT3Axis.G, OT3Axis.Q]:
+                    if axis == OT3Axis.G:
+                        await self.home_gripper_jaw()
+                    elif axis == OT3Axis.Q:
                         await self._backend.home([axis])
                     else:
                         await self._home_axis(axis)
@@ -1206,16 +1211,6 @@ async def _home(self, axes: Sequence[OT3Axis]) -> None:
                 else:
                     await self._cache_current_position()
                     await self._cache_encoder_position()
-                    if axis == OT3Axis.G:
-                        try:
-                            self._gripper_handler.set_jaw_state(
-                                GripperJawState.HOMED_READY
-                            )
-                            self._gripper_handler.set_jaw_displacement(
-                                self._encoder_position[OT3Axis.G]
-                            )
-                        except GripperNotAttachedError:
-                            pass
 
     @ExecutionManagerProvider.wait_for_running
     async def home(

api/tests/opentrons/config/ot3_settings.py

@@ -110,7 +110,6 @@
     },
     "log_level": "NADA",
     "z_retract_distance": 10,
-    "grip_jaw_home_duty_cycle": 25,
     "safe_home_distance": 5,
     "deck_transform": [[-0.5, 0, 1], [0.1, -2, 4], [0, 0, -1]],
     "carriage_offset": (1, 2, 3),

api/tests/opentrons/hardware_control/test_moves.py

@@ -84,19 +84,18 @@ def mock_home(ot3_hardware):
 
 
 async def test_home(ot3_hardware, mock_home):
-    # this is only valid for Axis G, for other axes, check out test_ot3_api.py
     with mock.patch("opentrons.hardware_control.ot3api.deck_from_machine") as dfm_mock:
-        dfm_mock.return_value = {OT3Axis.G: 20}
-        await ot3_hardware._home([OT3Axis.G])
+        dfm_mock.return_value = {OT3Axis.X: 20}
+        await ot3_hardware._home([OT3Axis.X])
 
-        mock_home.assert_called_once_with([OT3Axis.G])
+        mock_home.assert_called_once_with([OT3Axis.X])
         assert dfm_mock.call_count == 2
         dfm_mock.assert_called_with(
             mock_home.return_value,
             ot3_hardware._transforms.deck_calibration.attitude,
             ot3_hardware._transforms.carriage_offset,
         )
-    assert ot3_hardware._current_position[OT3Axis.G] == 20
+    assert ot3_hardware._current_position[OT3Axis.X] == 20
 
 
 async def test_home_unmet(ot3_hardware, mock_home):

api/tests/opentrons/hardware_control/test_ot3_api.py

@@ -420,10 +420,11 @@ async def test_liquid_probe(
     fake_liquid_settings: LiquidProbeSettings,
     mock_instrument_handlers: Tuple[Mock],
     mock_current_position_ot3: AsyncMock,
+    mock_ungrip: AsyncMock,
     mock_home_plunger: AsyncMock,
 ) -> None:
+    mock_ungrip.return_value = None
     backend = ot3_hardware.managed_obj._backend
-
     await ot3_hardware.home()
     mock_move_to.return_value = None
 
@@ -490,9 +491,10 @@ async def test_liquid_sensing_errors(
     mock_instrument_handlers: Tuple[Mock],
     mock_current_position_ot3: AsyncMock,
     mock_home_plunger: AsyncMock,
+    mock_ungrip: AsyncMock,
 ) -> None:
     backend = ot3_hardware.managed_obj._backend
-
+    mock_ungrip.return_value = None
     await ot3_hardware.home()
     mock_move_to.return_value = None
 
@@ -787,6 +789,8 @@ async def test_gripper_action(
     mock_ungrip.assert_called_once()
     mock_ungrip.reset_mock()
     await ot3_hardware.home([OT3Axis.G])
+    mock_ungrip.assert_called_once()
+    mock_ungrip.reset_mock()
     await ot3_hardware.grip(5.0)
     mock_grip.assert_called_once_with(
         gc.duty_cycle_by_force(5.0, gripper_config.grip_force_profile),
@@ -956,7 +960,9 @@ async def test_save_instrument_offset(
 async def test_pick_up_tip_full_tiprack(
     ot3_hardware: ThreadManager[OT3API],
     mock_instrument_handlers: Tuple[Mock],
+    mock_ungrip: AsyncMock,
 ) -> None:
+    mock_ungrip.return_value = None
     await ot3_hardware.home()
     _, pipette_handler = mock_instrument_handlers
     backend = ot3_hardware.managed_obj._backend