def _read_raw_packet(self):
"""
Reads a raw line of data from the Arduino.
"""
with self._serial_read_lock:
data = (self._serial.readline() or '').strip()
# self._serial.reset_input_buffer()
if data:
self.print('read raw data:', data)
if data[0] == c.ID_HASH:
# Check for new hash.
try:
self.expected_hash = int(data[1:].strip())
except (TypeError, ValueError) as e:
traceback.print_exc(file=sys.stderr)
elif self.expected_hash:
# Validate packet.
packet = Packet.from_string(data)
if packet.hash != self.expected_hash:
# if self.verbose:
self.print('Invalid packet read due to hash mismatch:',
packet)
data = ''
if data:
# Record a successful read.
self.last_read = time.time()
return data
def _read_packet(self):
"""
Reads a packet from the Arduino.
"""
data = self._read_raw_packet()
if data:
packet = Packet.from_string(data)
# Keep a receipt of when we receive acknowledgments so the write thread
# knows when to stop waiting.
if packet.data == c.OK:
with self._acks_lock:
self._acks[packet.id] = time.time()
# Record pong so we know Arduino is still alive.
# if packet.id == c.ID_PONG:
# self.last_pong = time.time()
self.read_count += 1
if packet.non_get_id in c.ALL_IDS:
self.packet_counts[packet.non_get_id] += 2
return packet
