diff options
| -rw-r--r-- | broadlink/__init__.py | 40 | ||||
| -rw-r--r-- | setup.py | 2 |
2 files changed, 38 insertions, 4 deletions
diff --git a/broadlink/__init__.py b/broadlink/__init__.py index c9e581fd6c78..49309c21f12f 100644 --- a/broadlink/__init__.py +++ b/broadlink/__init__.py @@ -701,10 +701,44 @@ class hysen(device): # Returns decrypted payload # New behaviour: raises a ValueError if the device response indicates an error or CRC check fails # The function prepends length (2 bytes) and appends CRC + + def calculate_crc16(self, input_data): + from ctypes import c_ushort + crc16_tab = [] + crc16_constant = 0xA001 + + for i in range(0, 256): + crc = c_ushort(i).value + for j in range(0, 8): + if (crc & 0x0001): + crc = c_ushort(crc >> 1).value ^ crc16_constant + else: + crc = c_ushort(crc >> 1).value + crc16_tab.append(hex(crc)) + + try: + is_string = isinstance(input_data, str) + is_bytes = isinstance(input_data, bytes) + + if not is_string and not is_bytes: + raise Exception("Please provide a string or a byte sequence " + "as argument for calculation.") + + crcValue = 0xffff + + for c in input_data: + d = ord(c) if is_string else c + tmp = crcValue ^ d + rotated = c_ushort(crcValue >> 8).value + crcValue = rotated ^ int(crc16_tab[(tmp & 0x00ff)], 0) + + return crcValue + except Exception as e: + print("EXCEPTION(calculate): {}".format(e)) + def send_request(self, input_payload): - from PyCRC.CRC16 import CRC16 - crc = CRC16(modbus_flag=True).calculate(bytes(input_payload)) + crc = calculate_crc16(bytes(input_payload)) # first byte is length, +2 for CRC16 request_payload = bytearray([len(input_payload) + 2, 0x00]) @@ -728,7 +762,7 @@ class hysen(device): response_payload_len = response_payload[0] if response_payload_len + 2 > len(response_payload): raise ValueError('hysen_response_error', 'first byte of response is not length') - crc = CRC16(modbus_flag=True).calculate(bytes(response_payload[2:response_payload_len])) + crc = calculate_crc16(bytes(response_payload[2:response_payload_len])) if (response_payload[response_payload_len] == crc & 0xFF) and ( response_payload[response_payload_len + 1] == (crc >> 8) & 0xFF): return response_payload[2:response_payload_len] diff --git a/setup.py b/setup.py index 6183611dedb4..b7fe6b6f221e 100644 --- a/setup.py +++ b/setup.py @@ -15,7 +15,7 @@ setup( url='http://github.com/mjg59/python-broadlink', packages=find_packages(), scripts=[], - install_requires=['cryptography>=2.1.1', 'PyCRC'], + install_requires=['cryptography>=2.1.1'], description='Python API for controlling Broadlink IR controllers', classifiers=[ 'Development Status :: 4 - Beta', |