def testSendPeriodicAndChangeFrameAndStopExtended(self):
"""Start periodic CAN transmission, update frame data (not interval), and finally stop transmission."""
RESULT_ALLOWED_DIFFERENCE = 5 # Number of missed frames, or when stopping sending too late.
TRANSMISSION_INTERVAL_MILLISECONDS = 20
MEASUREMENT_TIME = 1 # seconds
self.simulated_can_process = subprocess.Popen(['candump', VIRTUAL_CAN_BUS_NAME], shell=False,
universal_newlines=True,
stdout=subprocess.PIPE, stderr=subprocess.PIPE)
time.sleep(0.1)
frame_zeros = canframe.CanFrame(self.FRAME_ID_SEND, b'\x00\x00\x00\x00\x00\x00\x00\x00', 'extended')
frame_ones = canframe.CanFrame(self.FRAME_ID_SEND, b'\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF', 'extended')
self.interface.setup_periodic_send(frame_zeros, TRANSMISSION_INTERVAL_MILLISECONDS)
time.sleep(MEASUREMENT_TIME)
self.interface.setup_periodic_send(frame_ones, restart_timer=False)
time.sleep(MEASUREMENT_TIME)
self.interface.stop_periodic_send(self.FRAME_ID_SEND, 'extended')
time.sleep(MEASUREMENT_TIME)
self.simulated_can_process.terminate()
out, err = self.simulated_can_process.communicate()
projected_number_of_frames = MEASUREMENT_TIME * 1000 / TRANSMISSION_INTERVAL_MILLISECONDS
number_of_frames_zeros = out.count(" {:08.0f} [8] 00 00 00 00 00 00 00 00".format(self.FRAME_ID_SEND))
self.assertGreaterEqual(number_of_frames_zeros, projected_number_of_frames - RESULT_ALLOWED_DIFFERENCE)
self.assertLessEqual(number_of_frames_zeros, projected_number_of_frames + RESULT_ALLOWED_DIFFERENCE)
number_of_frames_ones = out.count(" {:08.0f} [8] FF FF FF FF FF FF FF FF".format(self.FRAME_ID_SEND))
self.assertGreaterEqual(number_of_frames_ones, projected_number_of_frames - RESULT_ALLOWED_DIFFERENCE)
self.assertLessEqual(number_of_frames_ones, projected_number_of_frames + RESULT_ALLOWED_DIFFERENCE)
def testConstructor(self):
frame1 = canframe.CanFrame(0x7FF, b'\x02', 'standard')
self.assertEqual(frame1.frame_id, 0x7FF)
self.assertEqual(frame1.frame_data, b'\x02')
self.assertEqual(frame1.frame_format, 'standard')
frame2 = canframe.CanFrame(0x1FFFFFFF, b'\x02\x03', 'extended')
self.assertEqual(frame2.frame_id, 0x1FFFFFFF)
self.assertEqual(frame2.frame_data, b'\x02\x03')
self.assertEqual(frame2.frame_format, 'extended')
def testConstructorNamedArguments(self):
frame = canframe.CanFrame(frame_id=3,
frame_data=b'\x04',
frame_format='extended')
self.assertEqual(frame.frame_id, 3)
self.assertEqual(frame.frame_data, b'\x04')
self.assertEqual(frame.frame_format, 'extended')
def testStopNonexistingPeriodicTask(self):
self.assertRaises(exceptions.CanException, self.interface.stop_periodic_send, self.FRAME_ID_SEND)
TRANSMISSION_INTERVAL_MILLISECONDS = 20
frame_zeros = canframe.CanFrame(self.FRAME_ID_SEND, b'\x00\x00\x00\x00\x00\x00\x00\x00', 'standard')
self.interface.setup_periodic_send(frame_zeros, TRANSMISSION_INTERVAL_MILLISECONDS)
self.assertRaises(exceptions.CanException, self.interface.stop_periodic_send, self.FRAME_ID_SEND, 'extended')
def testSignalvalueGetDoubleLittle(self):
testsig1 = cansignal.CanSignalDefinition('testsignal1',
0,
64,
endianness='little',
signaltype='double')
# Example from https://en.wikipedia.org/wiki/Single-precision_floating-point_format
frame1 = canframe.CanFrame(1, b'\x00\x00\x00\x00\x00\x00\xF0\x3F')
self.assertAlmostEqual(frame1.get_signalvalue(testsig1), 1.0)
def testSignalvalueGetSingle(self):
testsig1 = cansignal.CanSignalDefinition('testsignal1',
56,
32,
endianness='big',
signaltype='single')
# Example from https://en.wikipedia.org/wiki/Single-precision_floating-point_format
frame1 = canframe.CanFrame(1, b'\x00\x00\x00\x00\x3E\x20\x00\x00')
self.assertAlmostEqual(frame1.get_signalvalue(testsig1), 0.15625)
def testSignalvalueGetDouble(self):
testsig1 = cansignal.CanSignalDefinition('testsignal1',
56,
64,
endianness='big',
signaltype='double')
# Example from https://en.wikipedia.org/wiki/Single-precision_floating-point_format
frame1 = canframe.CanFrame(1, b'\x40\x00\x00\x00\x00\x00\x00\x00')
self.assertAlmostEqual(frame1.get_signalvalue(testsig1), 2.0)
frame1 = canframe.CanFrame(1, b'\x3F\xF0\x00\x00\x00\x00\x00\x00')
self.assertAlmostEqual(frame1.get_signalvalue(testsig1), 1.0)
frame1 = canframe.CanFrame(1, b'\x3F\xF0\x00\x00\x00\x00\x00\x01')
self.assertAlmostEqual(frame1.get_signalvalue(testsig1), 1.0)
frame1 = canframe.CanFrame(1, b'\x7F\xEF\xFF\xFF\xFF\xFF\xFF\xFF')
self.assertAlmostEqual(frame1.get_signalvalue(testsig1),
1.7976931348623157e308)
def testSignalvalueSetDoubleLittle(self):
testsig1 = cansignal.CanSignalDefinition('testsignal1',
0,
64,
endianness='little',
signaltype='double')
frame1 = canframe.CanFrame(1, b'\x00\x00\x00\x00\x00\x00\x00\x00')
# Example from https://en.wikipedia.org/wiki/Double-precision_floating-point_format
frame1.set_signalvalue(testsig1, 2.0)
self.assertEqual(frame1.frame_data,
b'\x00\x00\x00\x00\x00\x00\x00\x40')
def testSendBcmFrame(self):
self.simulated_can_process = subprocess.Popen(['candump', VIRTUAL_CAN_BUS_NAME,
'-n', '1'],
shell=False, universal_newlines=True,
stdout=subprocess.PIPE, stderr=subprocess.PIPE)
time.sleep(0.1)
frame_to_send = canframe.CanFrame(FRAME_ID_SEND, b"\x02\x03\x00\x05\x04\x00\x00\x01")
self.canbus_bcm.send_frame(frame_to_send)
out, err = self.simulated_can_process.communicate(timeout=2)
known_result = "[8] 02 03 00 05 04 00 00 01"
self.assertIn(known_result, out)
def testSignalvalueSetSingleLittle(self):
testsig1 = cansignal.CanSignalDefinition('testsignal1',
32,
32,
endianness='little',
signaltype='single')
print(testsig1.get_descriptive_ascii_art())
frame1 = canframe.CanFrame(1, b'\x00\x00\x00\x00\x00\x00\x00\x00')
# Example from https://en.wikipedia.org/wiki/Single-precision_floating-point_format
frame1.set_signalvalue(testsig1, 0.15625)
self.assertEqual(frame1.frame_data,
b'\x00\x00\x00\x00\x00\x00\x20\x3E')
def setUp(self):
self.frame = canframe.CanFrame(1, b'\x00\x02\x00\x08\x00\x00\x00\xff')
self.testsig1 = cansignal.CanSignalDefinition(
'testsignal1', 56, 1) # Least significant bit in last byte
self.testsig2 = cansignal.CanSignalDefinition(
'testsignal2', 8, 16, endianness='big') # Two leftmost bytes
self.testsig3 = cansignal.CanSignalDefinition(
'testsignal3', 24, 16, endianness='little',
maxvalue=1200) # Two center bytes
self.testsig4 = cansignal.CanSignalDefinition(
'testsignal4', 48, 8, signaltype='signed') # Second last byte
self.frame_def = canframe_definition.CanFrameDefinition(
1, 'testmessage')
self.frame_def.signaldefinitions.append(self.testsig1)
self.frame_def.signaldefinitions.append(self.testsig2)
self.frame_def.signaldefinitions.append(self.testsig3)
self.frame_def.signaldefinitions.append(self.testsig4)
def testSetupPeriodicSendWrongType(self):
frame_zeros = canframe.CanFrame(self.FRAME_ID_SEND, b'\x00\x00\x00\x00\x00\x00\x00\x00')
self.assertRaises(exceptions.CanException, self.interface.setup_periodic_send, 1)
self.assertRaises(exceptions.CanException, self.interface.setup_periodic_send, frame_zeros, "ABC")
