299 m add delay countdown (#126)

* driver's wait() uses time.sleep and checks threading Events to exit early

* adds traceable to delay

* using timestamp to track delay progress

* adds test

* modifies test_wait to expect delay within +/-0.1

* removed countdown notification, replaces with just start and finished notifications

* adds countdown back to notifications

Author: andySigler

opentrons/drivers/motor.py

@@ -12,6 +12,7 @@
 
 from opentrons.util.log import get_logger
 from opentrons.util.vector import Vector
+from opentrons.drivers.virtual_smoothie import VirtualSmoothie
 
 from opentrons.util import trace
 
@@ -500,12 +501,25 @@ def home(self, *axis):
         else:
             return False
 
-    def wait(self, sec):
-        ms = int((sec % 1.0) * 1000)
-        s = int(sec)
-        self.check_paused_stopped()
-        res = self.send_command(self.DWELL, S=s, P=ms)
-        return res == b'ok'
+    def wait(self, delay_time):
+        start_time = time.time()
+        end_time = start_time + delay_time
+        arguments = {'name': 'delay-start', 'time': delay_time}
+        trace.EventBroker.get_instance().notify(arguments)
+        if not isinstance(self.connection, VirtualSmoothie):
+            while time.time() + 1.0 < end_time:
+                self.check_paused_stopped()
+                time.sleep(1)
+                arguments = {
+                    'name': 'countdown',
+                    'countdown': int(end_time - time.time())
+                }
+                trace.EventBroker.get_instance().notify(arguments)
+            remaining_time = end_time - time.time()
+            time.sleep(max(0, remaining_time))
+        arguments = {'name': 'delay-finish'}
+        trace.EventBroker.get_instance().notify(arguments)
+        return True
 
     def calm_down(self):
         res = self.send_command(self.CALM_DOWN)

tests/opentrons/drivers/test_motor.py

@@ -1,3 +1,4 @@
+import time
 from threading import Thread
 import unittest
 
@@ -236,7 +237,19 @@ def test_send_command_with_kwargs(self):
         self.assertTrue(success)
 
     def test_wait(self):
+        # set connection to be something other than VirtualSmoothie
+        self.motor.connection = int()
+        start_time = time.time()
         success = self.motor.wait(1.234)
+        end_time = time.time()
+        self.assertAlmostEquals(end_time - start_time, 1.234, places=1)
+        self.assertTrue(success)
+
+        self.motor.connection = int()
+        start_time = time.time()
+        success = self.motor.wait(1.0)
+        end_time = time.time()
+        self.assertAlmostEquals(end_time - start_time, 1.0, places=1)
         self.assertTrue(success)
 
     def test_wait_for_arrival(self):