def test_uart_speed(self):
bits = 8
baud = 9600
polarity = uart.UARTConfig.IdleHigh
parity = None
stop_bits = 1
char_count = 1000
data = [random.randint(0, 255) for _ in xrange(char_count)]
edges = list(
uart.uart_synth(data,
bits,
baud,
parity=parity,
stop_bits=stop_bits))
iterations = 10
self._t_start = time.time()
for _ in xrange(iterations):
records = list(uart.uart_decode(iter(edges), bits=bits, polarity=polarity, parity=parity, stop_bits=stop_bits, \
stream_type=stream.StreamType.Edges, baud_rate=baud))
characters_processed = iterations * char_count
return (iterations, characters_processed, 'characters')
def test_uart_hello(self):
bits = 8
polarity = uart.UARTConfig.IdleLow
parity = 'even'
stop_bits = 2
message = 'Hello, world!'
samples, sample_period, start_time = tsup.read_bin_file('test/data/uart_hello_8e2.bin')
txd = stream.samples_to_sample_stream(samples, sample_period, start_time)
frames = list(uart.uart_decode(txd, bits=bits, polarity=polarity, parity=parity, stop_bits=stop_bits))
ok_status = True
for f in frames:
if f.nested_status() != stream.StreamStatus.Ok:
ok_status = False
break
self.assertTrue(ok_status, 'Decoded data has non-Ok status')
# Check the message bytes
dmsg = ''.join([chr(d.data) for d in frames])
self.assertEqual(message, dmsg, 'Message mismatch. Expected: "{}" Got: "{}"'.format(message, dmsg))
bits = 8
polarity = uart.UARTConfig.IdleLow
parity = None
stop_bits = 1
message = 'Hello, world!'
samples, sample_period, start_time = tsup.read_bin_file('test/data/uart_hello.bin')
txd = stream.samples_to_sample_stream(samples, sample_period, start_time)
frames = list(uart.uart_decode(txd, bits=bits, polarity=polarity, parity=parity, stop_bits=stop_bits))
ok_status = True
for f in frames:
if f.nested_status() != stream.StreamStatus.Ok:
ok_status = False
break
self.assertTrue(ok_status, 'Decoded data has non-Ok status')
# Check the message bytes
dmsg = ''.join([chr(d.data) for d in frames])
self.assertEqual(message, dmsg, 'Message 2 mismatch. Expected: "{}" Got: "{}"'.format(message, dmsg))
def test_uart_decode(self):
self.test_name = 'UART message'
self.trial_count = 10
for i in xrange(self.trial_count):
self.update_progress(i + 1)
msg = []
for _ in xrange(20):
msg.append(chr(random.choice(xrange(ord('0'), ord('z')))))
msg = ''.join(msg)
baud = random.choice((110, 300, 600, 1200, 2400, 4800, 9600, 14400, 19200, 28800, 38400, \
56000, 57600, 115200, 128000, 153600, 230400, 256000, 460800, 921600))
sample_rate = baud * 100.0
rise_time = sigp.min_rise_time(
sample_rate) * 10.0 # 10x min rise time
parity = random.choice((None, 'even', 'odd'))
bits = random.choice((7, 8, 9))
#print('\nTRIAL {}: msg="{}", baud={}, parity={}, bits={}'.format(i, msg, baud, parity, bits))
edges = uart.uart_synth(bytearray(msg.encode('utf-8')),
bits,
baud,
parity=parity,
idle_start=100.0 / sample_rate)
samples = sigp.synth_wave(edges,
sample_rate,
rise_time,
ripple_db=60)
noisy = sigp.amplify(sigp.noisify(samples, snr_db=20), gain=-15.0)
waveform = list(noisy)
frames = uart.uart_decode(iter(waveform),
bits=bits,
polarity=uart.UARTConfig.IdleLow,
parity=parity,
baud_rate=None)
frames = list(frames)
#print(''.join(str(d) for d in frames))
decoded_msg = ''.join(str(d) for d in frames)
self.assertEqual(msg, decoded_msg, \
"Message not decoded successfully msg:'{0}', baud:{1}, parity:{2}, bits:{3}".format(msg, \
baud, parity, bits))
def test_uart_speed(self):
bits = 8
baud = 9600
polarity = uart.UARTConfig.IdleHigh
parity = None
stop_bits = 1
char_count = 1000
data = [random.randint(0,255) for _ in xrange(char_count)]
edges = list(uart.uart_synth(data, bits, baud, parity=parity, stop_bits=stop_bits))
iterations = 10
self._t_start = time.time()
for _ in xrange(iterations):
records = list(uart.uart_decode(iter(edges), bits=bits, polarity=polarity, parity=parity, stop_bits=stop_bits, \
stream_type=stream.StreamType.Edges, baud_rate=baud))
characters_processed = iterations * char_count
return (iterations, characters_processed, 'characters')
def test_uart_decode(self):
self.test_name = 'UART message'
self.trial_count = 10
for i in xrange(self.trial_count):
self.update_progress(i+1)
msg = []
for _ in xrange(20):
msg.append(chr(random.choice(xrange(ord('0'), ord('z')) )))
msg = ''.join(msg)
baud = random.choice((110, 300, 600, 1200, 2400, 4800, 9600, 14400, 19200, 28800, 38400, \
56000, 57600, 115200, 128000, 153600, 230400, 256000, 460800, 921600))
sample_rate = baud * 100.0
rise_time = sigp.min_rise_time(sample_rate) * 10.0 # 10x min rise time
parity = random.choice((None, 'even', 'odd'))
bits = random.choice((7, 8, 9))
#print('\nTRIAL {}: msg="{}", baud={}, parity={}, bits={}'.format(i, msg, baud, parity, bits))
edges = uart.uart_synth(bytearray(msg.encode('utf-8')), bits, baud, parity=parity, idle_start=100.0 / sample_rate)
samples = sigp.synth_wave(edges, sample_rate, rise_time, ripple_db=60)
noisy = sigp.amplify(sigp.noisify(samples, snr_db=20), gain=-15.0)
waveform = list(noisy)
frames = uart.uart_decode(iter(waveform), bits=bits, polarity=uart.UARTConfig.IdleLow, parity=parity, baud_rate=None)
frames = list(frames)
#print(''.join(str(d) for d in frames))
decoded_msg = ''.join(str(d) for d in frames)
self.assertEqual(msg, decoded_msg, \
"Message not decoded successfully msg:'{0}', baud:{1}, parity:{2}, bits:{3}".format(msg, \
baud, parity, bits))
def iso_k_line_decode(stream_data, min_message_interval=7.0e-3, logic_levels=None, stream_type=stream.StreamType.Samples):
'''Decode ISO9141 and ISO14230 data streams
This is a generator function that can be used in a pipeline of waveform
procesing operations.
Sample streams are a sequence of SampleChunk Objects. Edge streams are a sequence
of 2-tuples of (time, int) pairs. The type of stream is identified by the stream_type
parameter. Sample streams will be analyzed to find edge transitions representing
0 and 1 logic states of the waveforms. With sample streams, an initial block of data
is consumed to determine the most likely logic levels in the signal.
stream_data (iterable of SampleChunk objects or (float, int) pairs)
A sample stream or edge stream of K-line messages.
min_message_interval (float)
The minimum time between bytes for identifying the end and start
of messages. For ISO14230 this is used in addition to the message length encoded
in the header.
logic_levels ((float, float) or None)
Optional pair that indicates (low, high) logic levels of the sample
stream. When present, auto level detection is disabled. This has no effect on
edge streams.
stream_type (streaming.StreamType)
A StreamType value indicating that the stream parameter represents either Samples
or Edges
Yields a series of KLineStreamMessage objects.
Raises AutoLevelError if stream_type = Samples and the logic levels cannot
be determined.
'''
if stream_type == stream.StreamType.Samples:
if logic_levels is None:
samp_it, logic_levels = check_logic_levels(stream_data)
else:
samp_it = stream_data
edges = find_edges(samp_it, logic_levels, hysteresis=0.4)
else: # the stream is already a list of edges
edges = stream_data
bits = 8
parity = None
stop_bits = 1
polarity = uart.UARTConfig.IdleHigh
baud_rate = 10400
records_it = uart.uart_decode(edges, bits, parity, stop_bits, lsb_first=True, \
polarity=polarity, baud_rate=baud_rate, logic_levels=logic_levels, stream_type=stream.StreamType.Edges)
S_WAKEUP = 0
S_INIT = 1
S_START_MSG = 2
S_GET_MSG = 3
state = S_GET_MSG
wakeup_edges = []
init_bytes = []
protocol = KLineProtocol.Unknown
msg_bytes = []
prev_byte_end = 0.0
total_length = None
def get_msg_len(msg_bytes):
# Try to determine message length
if len(msg_bytes) > 0:
if msg_bytes[0].data & 0x80: #ISO14230
# Get length from first byte
length = msg_bytes[0].data & 0x3F
total_length = 3 + length + 1
if length == 0: # Header is 4-bytes long
if len(msg_bytes) >= 2: # 2nd byte is present
length = msg_bytes[1].data
total_length = 4 + length + 1
else:
return None
return total_length
else: #ISO9141
return None
else:
return None
def build_msg(protocol, msg_bytes):
# determine header length
header_length = 3
if protocol == KLineProtocol.ISO14230 and msg_bytes[0].data == 0x80:
header_length = 4
# Message must be at least h_l + 1 + 1 = 5 or 6 bytes long
if len(msg_bytes) >= header_length + 2:
sid_byte = msg_bytes[header_length]
msg_type = obd.OBD2MsgType.Request if sid_byte.data <= 0x3F else obd.OBD2MsgType.Response
if protocol == KLineProtocol.ISO9141:
header = ISO9141Header(option=msg_bytes[0], target=msg_bytes[1], source=msg_bytes[2])
elif protocol == KLineProtocol.ISO14230:
if header_length == 4:
length = msg_bytes[1]
target = msg_bytes[2]
source = msg_bytes[3]
else:
length = None
target = msg_bytes[1]
source = msg_bytes[2]
header = ISO14230Header(option=msg_bytes[0], target=target, source=source, \
length=length)
else: # Unknown protocol
header = ISO9141Header(option=msg_bytes[0], target=msg_bytes[1], source=msg_bytes[2])
msg = KLineMessage(msg_type, header, msg_bytes[header_length:-1], msg_bytes[-1])
status = KLineStreamStatus.ChecksumError if not msg.checksum_good() else stream.StreamStatus.Ok
obd_msg = KLineStreamMessage(msg, status)
obd_msg.annotate('frame', {}, stream.AnnotationFormat.Hidden)
for b in msg_bytes:
obd_msg.subrecords.append(b.subrecords[1])
obd_msg.subrecords[-1].annotate('data', {'_bits':8}, stream.AnnotationFormat.General)
obd_msg.subrecords[-1].kind = 'data'
for sr in obd_msg.subrecords[0:header_length]:
sr.style = 'addr'
sr.kind = 'header'
obd_msg.subrecords[-1].style = 'check'
obd_msg.subrecords[-1].status = status
obd_msg.subrecords[-1].kind = 'checksum'
else:
# Not enough bytes for proper K-line message
msg = KLineMessage(obd.OBD2MsgType.Unknown, None, msg_bytes, None)
obd_msg = KLineStreamMessage(msg, KLineStreamStatus.InvalidMessageError)
for b in msg_bytes:
obd_msg.subrecords.append(b.subrecords[1])
obd_msg.subrecords[-1].annotate('misc', {'_bits':8}, stream.AnnotationFormat.General)
return obd_msg
for r in records_it:
if r.data == 0x00 and r.status == uart.UARTStreamStatus.FramingError:
state = S_WAKEUP
wakeup_edges.append(r.start_time)
continue
if state == S_WAKEUP:
if not (r.data == 0x00 and r.status == uart.UARTStreamStatus.FramingError):
# not a BRK byte; wakeup has ended
bounds = (wakeup_edges[0], r.start_time)
wu = KLineWakeup(bounds, wakeup_edges)
wu.annotate('frame', {}, stream.AnnotationFormat.Hidden)
yield wu
wakeup_edges = []
if r.data == 0x55: # ISO9141 sync byte
protocol = KLineProtocol.ISO9141
init_bytes.append(r)
init_bytes_left = 4
state = S_INIT
elif r.data == 0xc1: # KWP2000 start comm. format byte
protocol = KLineProtocol.ISO14230
msg_bytes.append(r)
state = S_GET_MSG
prev_byte_end = r.end_time
else: # Unexpected data
se = stream.StreamEvent(r.start_time, kind='Bad init', \
status=KLineStreamStatus.BadInitError)
yield se
# We will just assume this is the start of a new message
msg_bytes.append(r)
state = S_GET_MSG
prev_byte_end = r.end_time
elif state == S_INIT:
# After 0x55 there are 4 more bytes remaining in the init sequence
# Key 1, Key 2, ~Key 2, ~Wakeup (0xCC typ.)
init_bytes.append(r)
init_bytes_left -= 1
if init_bytes_left == 0:
yield ISO9141Init(init_bytes)
init_bytes = []
state = S_START_MSG
prev_byte_end = r.end_time
elif state == S_START_MSG:
protocol = KLineProtocol.ISO14230 if r.data & 0x80 else KLineProtocol.ISO9141
msg_bytes.append(r)
state = S_GET_MSG
prev_byte_end = r.end_time
elif state == S_GET_MSG:
if len(msg_bytes) == 2:
total_length = get_msg_len(msg_bytes)
#print('### byte:', eng.eng_si(r.start_time, 's'), \
# eng.eng_si(r.start_time - prev_byte_end, 's'), hex(r.data))
if (r.start_time - prev_byte_end > min_message_interval and len(msg_bytes) > 0) or \
(total_length is not None and len(msg_bytes) == total_length):
# Previous message ended
msg = build_msg(protocol, msg_bytes)
yield msg
msg_bytes = []
total_length = None
# Determine the protocol of the next message
protocol = KLineProtocol.ISO14230 if r.data & 0x80 else KLineProtocol.ISO9141
msg_bytes.append(r)
prev_byte_end = r.end_time
# Handle final message
if len(msg_bytes) > 0:
msg = build_msg(protocol, msg_bytes)
yield msg
msg_bytes = []
# There may have been a partial wakeup pattern at the end of the stream
if len(wakeup_edges) > 0:
bounds = (wakeup_edges[0], prev_byte_end)
wu = KLineWakeup(bounds, wakeup_edges)
wu.annotate('frame', {}, stream.AnnotationFormat.Hidden)
yield wu
def test_uart_hello(self):
bits = 8
polarity = uart.UARTConfig.IdleLow
parity = 'even'
stop_bits = 2
message = 'Hello, world!'
samples, sample_period, start_time = tsup.read_bin_file(
'test/data/uart_hello_8e2.bin')
txd = stream.samples_to_sample_stream(samples, sample_period,
start_time)
frames = list(
uart.uart_decode(txd,
bits=bits,
polarity=polarity,
parity=parity,
stop_bits=stop_bits))
ok_status = True
for f in frames:
if f.nested_status() != stream.StreamStatus.Ok:
ok_status = False
break
self.assertTrue(ok_status, 'Decoded data has non-Ok status')
# Check the message bytes
dmsg = ''.join([chr(d.data) for d in frames])
self.assertEqual(
message, dmsg,
'Message mismatch. Expected: "{}" Got: "{}"'.format(message, dmsg))
bits = 8
polarity = uart.UARTConfig.IdleLow
parity = None
stop_bits = 1
message = 'Hello, world!'
samples, sample_period, start_time = tsup.read_bin_file(
'test/data/uart_hello.bin')
txd = stream.samples_to_sample_stream(samples, sample_period,
start_time)
frames = list(
uart.uart_decode(txd,
bits=bits,
polarity=polarity,
parity=parity,
stop_bits=stop_bits))
ok_status = True
for f in frames:
if f.nested_status() != stream.StreamStatus.Ok:
ok_status = False
break
self.assertTrue(ok_status, 'Decoded data has non-Ok status')
# Check the message bytes
dmsg = ''.join([chr(d.data) for d in frames])
self.assertEqual(
message, dmsg,
'Message 2 mismatch. Expected: "{}" Got: "{}"'.format(
message, dmsg))
def iso_k_line_decode(stream_data,
min_message_interval=7.0e-3,
logic_levels=None,
stream_type=stream.StreamType.Samples):
'''Decode ISO9141 and ISO14230 data streams
This is a generator function that can be used in a pipeline of waveform
procesing operations.
Sample streams are a sequence of SampleChunk Objects. Edge streams are a sequence
of 2-tuples of (time, int) pairs. The type of stream is identified by the stream_type
parameter. Sample streams will be analyzed to find edge transitions representing
0 and 1 logic states of the waveforms. With sample streams, an initial block of data
is consumed to determine the most likely logic levels in the signal.
stream_data (iterable of SampleChunk objects or (float, int) pairs)
A sample stream or edge stream of K-line messages.
min_message_interval (float)
The minimum time between bytes for identifying the end and start
of messages. For ISO14230 this is used in addition to the message length encoded
in the header.
logic_levels ((float, float) or None)
Optional pair that indicates (low, high) logic levels of the sample
stream. When present, auto level detection is disabled. This has no effect on
edge streams.
stream_type (streaming.StreamType)
A StreamType value indicating that the stream parameter represents either Samples
or Edges
Yields a series of KLineStreamMessage objects.
Raises AutoLevelError if stream_type = Samples and the logic levels cannot
be determined.
'''
if stream_type == stream.StreamType.Samples:
if logic_levels is None:
samp_it, logic_levels = check_logic_levels(stream_data)
else:
samp_it = stream_data
edges = find_edges(samp_it, logic_levels, hysteresis=0.4)
else: # the stream is already a list of edges
edges = stream_data
bits = 8
parity = None
stop_bits = 1
polarity = uart.UARTConfig.IdleHigh
baud_rate = 10400
records_it = uart.uart_decode(edges, bits, parity, stop_bits, lsb_first=True, \
polarity=polarity, baud_rate=baud_rate, logic_levels=logic_levels, stream_type=stream.StreamType.Edges)
S_WAKEUP = 0
S_INIT = 1
S_START_MSG = 2
S_GET_MSG = 3
state = S_GET_MSG
wakeup_edges = []
init_bytes = []
protocol = KLineProtocol.Unknown
msg_bytes = []
prev_byte_end = 0.0
total_length = None
def get_msg_len(msg_bytes):
# Try to determine message length
if len(msg_bytes) > 0:
if msg_bytes[0].data & 0x80: #ISO14230
# Get length from first byte
length = msg_bytes[0].data & 0x3F
total_length = 3 + length + 1
if length == 0: # Header is 4-bytes long
if len(msg_bytes) >= 2: # 2nd byte is present
length = msg_bytes[1].data
total_length = 4 + length + 1
else:
return None
return total_length
else: #ISO9141
return None
else:
return None
def build_msg(protocol, msg_bytes):
# determine header length
header_length = 3
if protocol == KLineProtocol.ISO14230 and msg_bytes[0].data == 0x80:
header_length = 4
# Message must be at least h_l + 1 + 1 = 5 or 6 bytes long
if len(msg_bytes) >= header_length + 2:
sid_byte = msg_bytes[header_length]
msg_type = obd.OBD2MsgType.Request if sid_byte.data <= 0x3F else obd.OBD2MsgType.Response
if protocol == KLineProtocol.ISO9141:
header = ISO9141Header(option=msg_bytes[0],
target=msg_bytes[1],
source=msg_bytes[2])
elif protocol == KLineProtocol.ISO14230:
if header_length == 4:
length = msg_bytes[1]
target = msg_bytes[2]
source = msg_bytes[3]
else:
length = None
target = msg_bytes[1]
source = msg_bytes[2]
header = ISO14230Header(option=msg_bytes[0], target=target, source=source, \
length=length)
else: # Unknown protocol
header = ISO9141Header(option=msg_bytes[0],
target=msg_bytes[1],
source=msg_bytes[2])
msg = KLineMessage(msg_type, header, msg_bytes[header_length:-1],
msg_bytes[-1])
status = KLineStreamStatus.ChecksumError if not msg.checksum_good(
) else stream.StreamStatus.Ok
obd_msg = KLineStreamMessage(msg, status)
obd_msg.annotate('frame', {}, stream.AnnotationFormat.Hidden)
for b in msg_bytes:
obd_msg.subrecords.append(b.subrecords[1])
obd_msg.subrecords[-1].annotate(
'data', {'_bits': 8}, stream.AnnotationFormat.General)
obd_msg.subrecords[-1].kind = 'data'
for sr in obd_msg.subrecords[0:header_length]:
sr.style = 'addr'
sr.kind = 'header'
obd_msg.subrecords[-1].style = 'check'
obd_msg.subrecords[-1].status = status
obd_msg.subrecords[-1].kind = 'checksum'
else:
# Not enough bytes for proper K-line message
msg = KLineMessage(obd.OBD2MsgType.Unknown, None, msg_bytes, None)
obd_msg = KLineStreamMessage(msg,
KLineStreamStatus.InvalidMessageError)
for b in msg_bytes:
obd_msg.subrecords.append(b.subrecords[1])
obd_msg.subrecords[-1].annotate(
'misc', {'_bits': 8}, stream.AnnotationFormat.General)
return obd_msg
for r in records_it:
if r.data == 0x00 and r.status == uart.UARTStreamStatus.FramingError:
state = S_WAKEUP
wakeup_edges.append(r.start_time)
continue
if state == S_WAKEUP:
if not (r.data == 0x00
and r.status == uart.UARTStreamStatus.FramingError):
# not a BRK byte; wakeup has ended
bounds = (wakeup_edges[0], r.start_time)
wu = KLineWakeup(bounds, wakeup_edges)
wu.annotate('frame', {}, stream.AnnotationFormat.Hidden)
yield wu
wakeup_edges = []
if r.data == 0x55: # ISO9141 sync byte
protocol = KLineProtocol.ISO9141
init_bytes.append(r)
init_bytes_left = 4
state = S_INIT
elif r.data == 0xc1: # KWP2000 start comm. format byte
protocol = KLineProtocol.ISO14230
msg_bytes.append(r)
state = S_GET_MSG
prev_byte_end = r.end_time
else: # Unexpected data
se = stream.StreamEvent(r.start_time, kind='Bad init', \
status=KLineStreamStatus.BadInitError)
yield se
# We will just assume this is the start of a new message
msg_bytes.append(r)
state = S_GET_MSG
prev_byte_end = r.end_time
elif state == S_INIT:
# After 0x55 there are 4 more bytes remaining in the init sequence
# Key 1, Key 2, ~Key 2, ~Wakeup (0xCC typ.)
init_bytes.append(r)
init_bytes_left -= 1
if init_bytes_left == 0:
yield ISO9141Init(init_bytes)
init_bytes = []
state = S_START_MSG
prev_byte_end = r.end_time
elif state == S_START_MSG:
protocol = KLineProtocol.ISO14230 if r.data & 0x80 else KLineProtocol.ISO9141
msg_bytes.append(r)
state = S_GET_MSG
prev_byte_end = r.end_time
elif state == S_GET_MSG:
if len(msg_bytes) == 2:
total_length = get_msg_len(msg_bytes)
#print('### byte:', eng.eng_si(r.start_time, 's'), \
# eng.eng_si(r.start_time - prev_byte_end, 's'), hex(r.data))
if (r.start_time - prev_byte_end > min_message_interval and len(msg_bytes) > 0) or \
(total_length is not None and len(msg_bytes) == total_length):
# Previous message ended
msg = build_msg(protocol, msg_bytes)
yield msg
msg_bytes = []
total_length = None
# Determine the protocol of the next message
protocol = KLineProtocol.ISO14230 if r.data & 0x80 else KLineProtocol.ISO9141
msg_bytes.append(r)
prev_byte_end = r.end_time
# Handle final message
if len(msg_bytes) > 0:
msg = build_msg(protocol, msg_bytes)
yield msg
msg_bytes = []
# There may have been a partial wakeup pattern at the end of the stream
if len(wakeup_edges) > 0:
bounds = (wakeup_edges[0], prev_byte_end)
wu = KLineWakeup(bounds, wakeup_edges)
wu.annotate('frame', {}, stream.AnnotationFormat.Hidden)
yield wu
def lin_decode(stream_data, enhanced_ids=None, baud_rate=None, logic_levels=None,\
stream_type=stream.StreamType.Samples, param_info=None):
'''Decode a LIN data stream
This is a generator function that can be used in a pipeline of waveform
procesing operations.
Sample streams are a sequence of SampleChunk Objects. Edge streams are a sequence
of 2-tuples of (time, int) pairs. The type of stream is identified by the stream_type
parameter. Sample streams will be analyzed to find edge transitions representing
0 and 1 logic states of the waveforms. With sample streams, an initial block of data
is consumed to determine the most likely logic levels in the signal.
stream_data (iterable of SampleChunk objects or (float, int) pairs)
A sample stream or edge stream representing a LIN signal.
enhanced_ids (sequence of int or None)
An optional sequence of frame IDs that are to use LIN 2.x enhanced checksums.
If None, the checksum type is guessed by trying both methods to see if one matches
decoded checksum.
baud_rate (int or None)
The baud rate of the stream. If None, the first 50 edges will be analyzed to
automatically determine the most likely baud rate for the stream. On average
50 edges will occur after 11 bytes have been captured.
logic_levels ((float, float) or None)
Optional pair that indicates (low, high) logic levels of the sample
stream. When present, auto level detection is disabled. This has no effect on
edge streams.
stream_type (streaming.StreamType)
A StreamType value indicating that the stream parameter represents either Samples
or Edges
param_info (dict or None)
An optional dictionary object that is used to monitor the results of
automatic baud detection.
Yields a series of LINStreamFrame objects.
Raises AutoLevelError if stream_type = Samples and the logic levels cannot
be determined.
Raises AutoBaudError if auto-baud is active and the baud rate cannot
be determined.
'''
if stream_type == stream.StreamType.Samples:
if logic_levels is None:
samp_it, logic_levels = ripyl.decode.check_logic_levels(stream_data)
else:
samp_it = stream_data
edges = ripyl.decode.find_edges(samp_it, logic_levels, hysteresis=0.4)
else: # the stream is already a list of edges
edges = stream_data
bits = 8
parity = None
stop_bits = 1
polarity = uart.UARTConfig.IdleHigh
records_it = uart.uart_decode(edges, bits, parity, stop_bits, lsb_first=True, \
polarity=polarity, baud_rate=baud_rate, use_std_baud=False, logic_levels=logic_levels, \
stream_type=stream.StreamType.Edges, param_info=param_info)
S_NEED_BREAK = 0
S_SYNC = 1
S_DATA = 2
state = S_NEED_BREAK
raw_bytes = []
frame_start = 0.0
next_frame_start = 0.0
frame_complete = False
for r in records_it:
# Look for a break condition
if state == S_NEED_BREAK:
if r.data == 0 and r.status == uart.UARTStreamStatus.FramingError:
frame_start = r.start_time
state = S_SYNC
elif state == S_SYNC:
if r.data == 0x55:
raw_bytes = []
state = S_DATA
else:
state = S_NEED_BREAK
elif state == S_DATA:
# Collect frame bytes until we see another break or we have 10 bytes (1 pid + 8 data + 1 checksum)
if r.data == 0 and r.status == uart.UARTStreamStatus.FramingError:
next_frame_start = r.start_time
frame_complete = True
state = S_SYNC
else:
raw_bytes.append(r)
if len(raw_bytes) >= 10:
frame_complete = True
state = S_NEED_BREAK
if frame_complete:
sf = _make_lin_frame(raw_bytes, frame_start, enhanced_ids)
frame_complete = False
frame_start = next_frame_start
raw_bytes = []
yield sf
if len(raw_bytes) > 0: # Partial frame remains
sf = _make_lin_frame(raw_bytes, frame_start, enhanced_ids)
yield sf
