fix packet length check (unreleased bug)

Author: fphammerle

CHANGELOG.md

@@ -6,7 +6,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 ### Changed
-- lock SPI device file
+- acquire `flock` on SPI device file
 - attribute `FT017TH.transceiver` is now private
 
 ### Added

tests/test_ft017th.py

@@ -154,7 +154,7 @@ def test_receive():
         sensor = wireless_sensor.FT017TH()
     measurement_iter = sensor.receive()
     packet = cc1101._ReceivedPacket(
-        data=b"\0" * 21, rssi_index=0, checksum_valid=True, link_quality_indicator=0
+        data=b"\0" * 23, rssi_index=0, checksum_valid=True, link_quality_indicator=0
     )
     with unittest.mock.patch.object(sensor, "_receive_packet") as receive_packet_mock:
         packet_queue = queue.Queue()
@@ -179,7 +179,7 @@ def test_receive():
         assert len(parse_transmission_args) == 1
         assert numpy.array_equal(
             parse_transmission_args[0],
-            numpy.array([255, 168] + [0] * 21, dtype=numpy.uint8),
+            numpy.array([255, 168] + [0] * 23, dtype=numpy.uint8),
         )
         with unittest.mock.patch.object(
             sensor, "_parse_transmission", return_value="dummy2"
@@ -197,7 +197,7 @@ def test_receive_failed_to_decode(caplog):
         sensor,
         "_receive_packet",
         return_value=cc1101._ReceivedPacket(
-            data=b"\0" * 21, rssi_index=0, checksum_valid=True, link_quality_indicator=0
+            data=b"\0" * 23, rssi_index=0, checksum_valid=True, link_quality_indicator=0
         ),
     ) as receive_packet_mock, unittest.mock.patch.object(
         sensor,
@@ -223,7 +223,7 @@ def test_receive_failed_to_decode(caplog):
     assert len(decode_error_log_records) == 2
     for error_index in range(2):
         assert decode_error_log_records[error_index][0] == (
-            "failed to decode _ReceivedPacket(RSSI -74dBm, 0x{}): ".format("00" * 21)
+            "failed to decode _ReceivedPacket(RSSI -74dBm, 0x{}): ".format("00" * 23)
             + "dummy error {}".format(error_index)
         )
         assert isinstance(

wireless_sensor/__init__.py

@@ -120,7 +120,7 @@ def __init__(self, unlock_spi_device: bool = False):
         self._transceiver = cc1101.CC1101(lock_spi_device=True)
         self._transmission_length_bytes = math.ceil(
             self._MESSAGE_LENGTH_BITS * self._MESSAGE_REPEATS / 8
-        ) - len(self._SYNC_WORD)
+        )
 
     def _configure_transceiver(self):
         self._transceiver.set_base_frequency_hertz(433.945e6)
@@ -133,7 +133,9 @@ def _configure_transceiver(self):
         self._transceiver.disable_checksum()
         self._transceiver.enable_manchester_code()
         self._transceiver.set_packet_length_mode(cc1101.PacketLengthMode.FIXED)
-        self._transceiver.set_packet_length_bytes(self._transmission_length_bytes)
+        self._transceiver.set_packet_length_bytes(
+            self._transmission_length_bytes - len(self._SYNC_WORD)
+        )
         # pylint: disable=protected-access; version pinned
         self._transceiver._set_filter_bandwidth(mantissa=3, exponent=3)