feat(api): add instrument cache to hardware control

Closes #2236

api/opentrons/hardware_control/__init__.py

@@ -83,6 +83,9 @@ def __init__(self,
         # {'X': 0.0, 'Y': 0.0, 'Z': 0.0, 'A': 0.0, 'B': 0.0, 'C': 0.0}
         self._current_position: dict = None
 
+        self._attached_instruments = {types.Mount.LEFT: None,
+                                      types.Mount.RIGHT: None}
+
     @classmethod
     def build_hardware_controller(
             cls, config: dict = None,
@@ -101,14 +104,16 @@ def build_hardware_controller(
 
     @classmethod
     def build_hardware_simulator(
-            cls, config: dict = None,
+            cls,
+            attached_instruments,
+            config: dict = None,
             loop: asyncio.AbstractEventLoop = None) -> 'API':
         """ Build a simulating hardware controller.
 
         This method may be used both on a real robot and on dev machines.
         Multiple simulating hardware controllers may be active at one time.
         """
-        return cls(simulator.Simulator(config, loop),
+        return cls(simulator.Simulator(attached_instruments, config, loop),
                    config=config, loop=loop)
 
     # Query API
@@ -141,7 +146,10 @@ async def identify(self, seconds):
 
     @_log_call
     async def cache_instrument_models(self):
-        pass
+        self._log.info("Updating instrument model cache")
+        for mount in types.Mount:
+            self._attached_instruments[mount] = \
+                self._backend.get_attached_instruments(mount)
 
     @_log_call
     async def update_smoothie_firmware(self, firmware_file):
@@ -203,7 +211,7 @@ async def _move(self, target_position: Dict[str, float]):
         try:
             self._backend.move(target_position)
         except Exception:
-            mod_log.exception('Move failed')
+            self._log.exception('Move failed')
             self._current_position.clear()
             raise
 

api/opentrons/hardware_control/controller.py

@@ -72,3 +72,6 @@ def move(self, target_position: Dict[str, float], home_flagged_axes=True):
 
     def home(self):
         return self._smoothie_driver.home()
+
+    def get_attached_instruments(self, mount):
+        return self._smoothie_driver.read_pipette_model(mount.name.lower())

api/opentrons/hardware_control/simulator.py

@@ -7,13 +7,17 @@ class Simulator:
     a robot with no smoothie connected.
     """
 
-    def __init__(self, config, loop):
+    def __init__(self, attached_instruments, config, loop):
         self._config = config
         self._loop = loop
+        self._attached_instruments = attached_instruments
 
     def move(self, target_position: Dict[str, float]):
         pass
 
     def home(self):
         # driver_3_0-> HOMED_POSITION
         return {'X': 418, 'Y': 353, 'Z': 218, 'A': 218, 'B': 19, 'C': 19}
+
+    def get_attached_instruments(self, mount):
+        return self._attached_instruments[mount]

api/tests/opentrons/hardware_control/test_instruments.py

@@ -0,0 +1,30 @@
+import pytest
+from opentrons import types
+from opentrons import hardware_control as hc
+
+
+async def test_cache_instruments(loop):
+    dummy_instruments_attached = {types.Mount.LEFT: 'model_abc',
+                                  types.Mount.RIGHT: None}
+    hw_api = hc.API.build_hardware_simulator(
+        attached_instruments=dummy_instruments_attached, loop=loop)
+    await hw_api.cache_instrument_models()
+    assert hw_api._attached_instruments == dummy_instruments_attached
+
+
+async def test_cache_instruments_hc(monkeypatch, hardware_controller_lockfile,
+                                    running_on_pi, loop):
+    if not hc.controller:
+        pytest.skip('hardware controller not available (probably windows)')
+
+    dummy_instruments_attached = {types.Mount.LEFT: 'model_abc',
+                                  types.Mount.RIGHT: None}
+    hw_api_cntrlr = hc.API.build_hardware_controller(loop=loop)
+
+    def mock_driver_method(mount):
+        attached_pipette = {'left': 'model_abc', 'right': None}
+        return attached_pipette[mount]
+    monkeypatch.setattr(hw_api_cntrlr._backend._smoothie_driver,
+                        'read_pipette_model', mock_driver_method)
+    await hw_api_cntrlr.cache_instrument_models()
+    assert hw_api_cntrlr._attached_instruments == dummy_instruments_attached

api/tests/opentrons/hardware_control/test_moves.py

@@ -2,23 +2,22 @@
 from opentrons import types
 from opentrons import hardware_control as hc
 
-if not hc.controller:
-    pytest.skip('hardware controller not available (probably windows)',
-                allow_module_level=True)
-
 
 @pytest.fixture
 def hardware_api(monkeypatch, loop):
     def mock_move(position):
         pass
-
-    hw_api = hc.API.build_hardware_simulator(loop=loop)
+    attached_pipettes = {types.Mount.LEFT: None, types.Mount.RIGHT: None}
+    hw_api = hc.API.build_hardware_simulator(
+        attached_instruments=attached_pipettes, loop=loop)
     monkeypatch.setattr(hw_api._backend, 'move', mock_move)
     return hw_api
 
 
 async def test_controller_home(loop):
-    c = hc.API.build_hardware_simulator(loop=loop)
+    attached_pipettes = {types.Mount.LEFT: None, types.Mount.RIGHT: None}
+    c = hc.API.build_hardware_simulator(
+        attached_instruments=attached_pipettes, loop=loop)
     await c.home()
     assert c._current_position == {'X': 418, 'Y': 353, 'Z': 218,
                                    'A': 218, 'B': 19, 'C': 19}