Convert Message.timestamp's seconds to the serial protocols milliseconds

hardbyte · hardbyte · commit 2ca71e0b6f8b · 2017-12-09T16:04:30.000+11:00
diff --git a/can/interfaces/serial/serial_can.py b/can/interfaces/serial/serial_can.py
@@ -75,10 +75,9 @@ def send(self, msg, timeout=None):
             This parameter will be ignored. The timeout value of the channel is
             used.
         """
-        if isinstance(msg.timestamp, float):
-            msg.timestamp = int(msg.timestamp)
+
         try:
-            timestamp = struct.pack('<I', msg.timestamp)
+            timestamp = struct.pack('<I', self.convert_to_integer_milliseconds(msg.timestamp))
         except Exception:
             raise ValueError('Timestamp is out of range')
         try:
@@ -97,12 +96,15 @@ def send(self, msg, timeout=None):
         byte_msg.append(0xBB)
         self.ser.write(byte_msg)
 
+    @staticmethod
+    def convert_to_integer_milliseconds(msg_timestamp):
+        return int(msg_timestamp * 1000)
+
     def recv(self, timeout=None):
         """
         Read a message from the serial device.
 
-        :param timeout:        # byte_msg = bytes([0xAA]) + timestamp + dlc + a_id + msg.data + \
-                 #   bytes([0xBB])
+        :param timeout:
             This parameter will be ignored. The timeout value of the channel is
             used.
         :returns:
@@ -135,10 +137,8 @@ def recv(self, timeout=None):
             rxd_byte = ord(self.ser.read())
             if rxd_byte == 0xBB:
                 # received message data okay
-                return Message(timestamp=timestamp, arbitration_id=arb_id,
-                               dlc=dlc, data=data)
-            else:
-                return None
+                return Message(timestamp=timestamp/1000,
+                               arbitration_id=arb_id,
+                               dlc=dlc,
+                               data=data)
 
-        else:
-            return None
diff --git a/examples/serial_com.py b/examples/serial_com.py
@@ -22,15 +22,11 @@
 import threading
 
 
-def time_millis():
-    return int(round(time.time() * 1000))
-
-
 def send_cyclic(bus, msg, stop_event):
     print("Start to send a message every 1s")
-    start_time = time_millis()
+    start_time = time.time()
     while not stop_event.is_set():
-        msg.timestamp = time_millis() - start_time
+        msg.timestamp = time.time() - start_time
         bus.send(msg)
         print("tx: {}".format(tx_msg))
         time.sleep(1)
diff --git a/test/serial_test.py b/test/serial_test.py
@@ -51,6 +51,7 @@ def reset(self):
 
 
 class SimpleSerialTest(unittest.TestCase):
+    MAX_TIMESTAMP = 0xFFFFFFFF / 1000
 
     def setUp(self):
         self.patcher = patch('serial.Serial')
@@ -117,16 +118,18 @@ def test_rx_tx_max_timestamp(self):
         """
         Tests the transfer with the highest possible timestamp
         """
-        msg = can.Message(timestamp=0xFFFFFFFF)
+
+        msg = can.Message(timestamp=self.MAX_TIMESTAMP)
         self.bus.send(msg)
         msg_receive = self.bus.recv()
         self.assertEqual(msg, msg_receive)
+        self.assertEqual(msg.timestamp, msg_receive.timestamp)
 
     def test_rx_tx_max_timestamp_error(self):
         """
         Tests for an exception with an out of range timestamp (max + 1)
         """
-        msg = can.Message(timestamp=0xFFFFFFFF+1)
+        msg = can.Message(timestamp=self.MAX_TIMESTAMP+1)
         self.assertRaises(ValueError, self.bus.send, msg)
 
     def test_rx_tx_min_timestamp(self):
@@ -137,6 +140,7 @@ def test_rx_tx_min_timestamp(self):
         self.bus.send(msg)
         msg_receive = self.bus.recv()
         self.assertEqual(msg, msg_receive)
+        self.assertEqual(msg.timestamp, msg_receive.timestamp)
 
     def test_rx_tx_min_timestamp_error(self):
         """
