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Fix some slcan issues #447

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Merged
christiansandberg merged 3 commits into from
Oct 6, 2018
Merged

Fix some slcan issues #447

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247df08
Fix some slcan issues
christiansandberg Oct 2, 2018
ad56c00
Fix issue with consecutive messages
christiansandberg Oct 3, 2018
cd391a6
Merge branch 'develop' into slcan-fixes
felixdivo Oct 5, 2018
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48 changes: 31 additions & 17 deletions can/interfaces/slcan.py
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Original file line number Diff line number Diff line change
Expand Up @@ -47,7 +47,10 @@ class slcanBus(BusABC):

_SLEEP_AFTER_SERIAL_OPEN = 2 # in seconds

LINE_TERMINATOR = b'\r'

def __init__(self, channel, ttyBaudrate=115200, bitrate=None,
sleep_after_open=_SLEEP_AFTER_SERIAL_OPEN,
rtscts=False, **kwargs):
"""
:param str channel:
Expand All @@ -59,6 +62,8 @@ def __init__(self, channel, ttyBaudrate=115200, bitrate=None,
Bitrate in bit/s
:param float poll_interval:
Poll interval in seconds when reading messages
:param float sleep_after_open:
Time to wait in seconds after opening serial connection
:param bool rtscts:
turn hardware handshake (RTS/CTS) on and off
"""
Expand All @@ -72,7 +77,9 @@ def __init__(self, channel, ttyBaudrate=115200, bitrate=None,
self.serialPortOrig = serial.serial_for_url(
channel, baudrate=ttyBaudrate, rtscts=rtscts)

time.sleep(self._SLEEP_AFTER_SERIAL_OPEN)
self._buffer = bytearray()

time.sleep(sleep_after_open)

if bitrate is not None:
self.close()
Expand All @@ -87,9 +94,7 @@ def __init__(self, channel, ttyBaudrate=115200, bitrate=None,
bitrate=None, rtscts=False, **kwargs)

def write(self, string):
Comment thread
felixdivo marked this conversation as resolved.
if not string.endswith('\r'):
string += '\r'
self.serialPortOrig.write(string.encode())
self.serialPortOrig.write(string.encode() + self.LINE_TERMINATOR)
self.serialPortOrig.flush()

def open(self):
Expand All @@ -107,12 +112,20 @@ def _recv_internal(self, timeout):
extended = False
frame = []

readStr = self.serialPortOrig.read_until(b'\r')
# Read everything that is already available
waiting = self.serialPortOrig.read(self.serialPortOrig.in_waiting)
self._buffer += waiting

if not readStr:
return None, False
else:
readStr = readStr.decode()
# Check if a complete message has been received
pos = self._buffer.find(self.LINE_TERMINATOR)
if pos == -1:
# Keep reading...
self._buffer += self.serialPortOrig.read_until(self.LINE_TERMINATOR)
Comment thread
felixdivo marked this conversation as resolved.
pos = self._buffer.find(self.LINE_TERMINATOR)

if pos != -1:
readStr = self._buffer[0:pos].decode()
del self._buffer[0:pos]
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@christiansandberg christiansandberg Oct 3, 2018

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Note to self: should be pos+1.

if readStr[0] == 'T':
# extended frame
canId = int(readStr[1:9], 16)
Expand All @@ -129,45 +142,46 @@ def _recv_internal(self, timeout):
elif readStr[0] == 'r':
# remote frame
canId = int(readStr[1:4], 16)
dlc = int(readStr[4])
remote = True
elif readStr[0] == 'R':
# remote extended frame
canId = int(readStr[1:9], 16)
dlc = int(readStr[9])
extended = True
remote = True

if canId is not None:
msg = Message(arbitration_id=canId,
extended_id=extended,
is_extended_id=extended,
timestamp=time.time(), # Better than nothing...
is_remote_frame=remote,
dlc=dlc,
data=frame)
return msg, False
else:
return None, False
return None, False

def send(self, msg, timeout=0):
def send(self, msg, timeout=None):
if timeout != self.serialPortOrig.write_timeout:
self.serialPortOrig.write_timeout = timeout

if msg.is_remote_frame:
if msg.is_extended_id:
sendStr = "R%08X0" % (msg.arbitration_id)
sendStr = "R%08X%d" % (msg.arbitration_id, msg.dlc)
else:
sendStr = "r%03X0" % (msg.arbitration_id)
sendStr = "r%03X%d" % (msg.arbitration_id, msg.dlc)
else:
if msg.is_extended_id:
sendStr = "T%08X%d" % (msg.arbitration_id, msg.dlc)
else:
sendStr = "t%03X%d" % (msg.arbitration_id, msg.dlc)

for i in range(0, msg.dlc):
sendStr += "%02X" % msg.data[i]
sendStr += "".join(["%02X" % b for b in msg.data])
self.write(sendStr)

def shutdown(self):
self.close()
self.serialPortOrig.close()

def fileno(self):
if hasattr(self.serialPortOrig, 'fileno'):
Expand Down
104 changes: 104 additions & 0 deletions test/test_slcan.py
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Original file line number Diff line number Diff line change
@@ -0,0 +1,104 @@
#!/usr/bin/env python
# coding: utf-8
import unittest
import can


class slcanTestCase(unittest.TestCase):

def setUp(self):
self.bus = can.Bus('loop://', bustype='slcan', sleep_after_open=0)
self.serial = self.bus.serialPortOrig
self.serial.read(self.serial.in_waiting)

def tearDown(self):
self.bus.shutdown()

def test_recv_extended(self):
self.serial.write(b'T12ABCDEF2AA55\r')
msg = self.bus.recv(0)
self.assertIsNotNone(msg)
self.assertEqual(msg.arbitration_id, 0x12ABCDEF)
self.assertEqual(msg.is_extended_id, True)
self.assertEqual(msg.is_remote_frame, False)
self.assertEqual(msg.dlc, 2)
self.assertSequenceEqual(msg.data, [0xAA, 0x55])

def test_send_extended(self):
msg = can.Message(arbitration_id=0x12ABCDEF,
is_extended_id=True,
data=[0xAA, 0x55])
self.bus.send(msg)
data = self.serial.read(self.serial.in_waiting)
self.assertEqual(data, b'T12ABCDEF2AA55\r')

def test_recv_standard(self):
self.serial.write(b't4563112233\r')
msg = self.bus.recv(0)
self.assertIsNotNone(msg)
self.assertEqual(msg.arbitration_id, 0x456)
self.assertEqual(msg.is_extended_id, False)
self.assertEqual(msg.is_remote_frame, False)
self.assertEqual(msg.dlc, 3)
self.assertSequenceEqual(msg.data, [0x11, 0x22, 0x33])

def test_send_standard(self):
msg = can.Message(arbitration_id=0x456,
is_extended_id=False,
data=[0x11, 0x22, 0x33])
self.bus.send(msg)
data = self.serial.read(self.serial.in_waiting)
self.assertEqual(data, b't4563112233\r')

def test_recv_standard_remote(self):
self.serial.write(b'r1238\r')
msg = self.bus.recv(0)
self.assertIsNotNone(msg)
self.assertEqual(msg.arbitration_id, 0x123)
self.assertEqual(msg.is_extended_id, False)
self.assertEqual(msg.is_remote_frame, True)
self.assertEqual(msg.dlc, 8)

def test_send_standard_remote(self):
msg = can.Message(arbitration_id=0x123,
is_extended_id=False,
is_remote_frame=True,
dlc=8)
self.bus.send(msg)
data = self.serial.read(self.serial.in_waiting)
self.assertEqual(data, b'r1238\r')

def test_recv_extended_remote(self):
self.serial.write(b'R12ABCDEF6\r')
msg = self.bus.recv(0)
self.assertIsNotNone(msg)
self.assertEqual(msg.arbitration_id, 0x12ABCDEF)
self.assertEqual(msg.is_extended_id, True)
self.assertEqual(msg.is_remote_frame, True)
self.assertEqual(msg.dlc, 6)

def test_send_extended_remote(self):
msg = can.Message(arbitration_id=0x12ABCDEF,
is_extended_id=True,
is_remote_frame=True,
dlc=6)
self.bus.send(msg)
data = self.serial.read(self.serial.in_waiting)
self.assertEqual(data, b'R12ABCDEF6\r')

def test_partial_recv(self):
self.serial.write(b'T12ABCDEF')
msg = self.bus.recv(0)
self.assertIsNone(msg)
self.serial.write(b'2AA55\rT12')
msg = self.bus.recv(0)
self.assertIsNotNone(msg)
self.assertEqual(msg.arbitration_id, 0x12ABCDEF)
self.assertEqual(msg.is_extended_id, True)
self.assertEqual(msg.is_remote_frame, False)
self.assertEqual(msg.dlc, 2)
self.assertSequenceEqual(msg.data, [0xAA, 0x55])


if __name__ == '__main__':
unittest.main()