fix(api): dont emit 0-duration moves (#13121)

They really stress the microcontrollers and they do absolutely nothing,
so let's not put them on the bus.

api/src/opentrons/hardware_control/backends/ot3utils.py

@@ -1,6 +1,7 @@
 """Shared utilities for ot3 hardware control."""
 from typing import Dict, Iterable, List, Set, Tuple, TypeVar, Sequence
 from typing_extensions import Literal
+from logging import getLogger
 from opentrons.config.defaults_ot3 import DEFAULT_CALIBRATION_AXIS_MAX_SPEED
 from opentrons.config.types import OT3MotionSettings, OT3CurrentSettings, GantryLoad
 from opentrons.hardware_control.types import (
@@ -52,6 +53,7 @@
     create_gripper_jaw_step,
     create_tip_action_step,
 )
+from opentrons_hardware.hardware_control.constants import interrupts_per_sec
 
 GRIPPER_JAW_HOME_TIME: float = 10
 GRIPPER_JAW_GRIP_TIME: float = 10
@@ -83,6 +85,8 @@
 
 USB_SUBSYSTEM = {target: subsystem for subsystem, target in SUBSYSTEM_USB.items()}
 
+LOG = getLogger(__name__)
+
 
 def axis_nodes() -> List["NodeId"]:
     return [
@@ -331,6 +335,11 @@ def create_move_group(
     for move in moves:
         unit_vector = move.unit_vector
         for block in move.blocks:
+            if block.time < (3.0 / interrupts_per_sec):
+                LOG.info(
+                    f"Skipping move block with time {block.time} (<{3.0/interrupts_per_sec})"
+                )
+                continue
             distances = unit_vector_multiplication(unit_vector, block.distance)
             node_id_distances = _convert_to_node_id_dict(distances)
             velocities = unit_vector_multiplication(unit_vector, block.initial_speed)

api/tests/opentrons/hardware_control/backends/test_ot3_utils.py

@@ -2,6 +2,7 @@
 from opentrons.hardware_control.backends import ot3utils
 from opentrons_hardware.firmware_bindings.constants import NodeId
 from opentrons.hardware_control.types import OT3Axis
+from numpy import float64 as f64
 
 
 def test_create_step() -> None:
@@ -16,6 +17,12 @@ def test_create_step() -> None:
     moves = [
         Move.build_dummy([OT3Axis.X, OT3Axis.Y, OT3Axis.Z_L, OT3Axis.Z_R, OT3Axis.P_L])
     ]
+    for block in moves[0].blocks:
+        block.distance = f64(25.0)
+        block.time = f64(1.0)
+        block.initial_speed = f64(25.0)
+        block.acceleration = f64(0.0)
+        block.final_speed = f64(25.0)
     present_nodes = [NodeId.gantry_x, NodeId.gantry_y, NodeId.head_l]
     move_group, final_pos = ot3utils.create_move_group(
         origin=origin,
@@ -27,6 +34,35 @@ def test_create_step() -> None:
         assert set(present_nodes) == set(step.keys())
 
 
+def test_filter_zero_duration_step() -> None:
+    origin = {
+        OT3Axis.X: 0,
+        OT3Axis.Y: 0,
+        OT3Axis.Z_L: 0,
+        OT3Axis.Z_R: 0,
+        OT3Axis.P_L: 0,
+        OT3Axis.P_R: 0,
+    }
+    moves = [
+        Move.build_dummy([OT3Axis.X, OT3Axis.Y, OT3Axis.Z_L, OT3Axis.Z_R, OT3Axis.P_L])
+    ]
+    for block in (moves[0].blocks[0], moves[0].blocks[1]):
+        block.distance = f64(25.0)
+        block.time = f64(1.0)
+        block.initial_speed = f64(25.0)
+        block.acceleration = f64(0.0)
+        block.final_speed = f64(25.0)
+    present_nodes = [NodeId.gantry_x, NodeId.gantry_y, NodeId.head_l]
+    move_group, final_pos = ot3utils.create_move_group(
+        origin=origin,
+        moves=moves,
+        present_nodes=present_nodes,
+    )
+    assert len(move_group) == 2
+    for step in move_group:
+        assert set(present_nodes) == set(step.keys())
+
+
 def test_nodeid_replace_head() -> None:
     assert ot3utils.replace_head_node(set([NodeId.head, NodeId.gantry_x])) == set(
         [NodeId.head_l, NodeId.head_r, NodeId.gantry_x]