55 lines
1.6 KiB
Python
55 lines
1.6 KiB
Python
def cal_crc8(data):
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'''
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计算1字节数据的CRC8
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'''
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crc = data
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poly = 0x31 #0x07 # 多项式x^8 + x^2 + x^1 + 1，即0x107，（根据原理）省略了最高位1而得0x07
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for i in range(8,0,-1):
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if ((crc & 0x80) >> 7) == 1: # 判断最高位是否为1，如果是需要异或，否则仅左移
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crc = (crc << 1) ^ poly
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else:
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crc = (crc << 1)
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return crc & 0xFF # 计算后需要进行截取
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def crc8(datas):
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'''
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计算数据的CRC8校验码
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'''
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length = len(datas)
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crc = 0x00
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for i in range(length):
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if i == 0:
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crc = cal_crc8(datas[0]) # 先计算第1个数据的CRC8
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else:
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crc = (crc ^ datas[i]) & 0xFF # 其余的均将上次的CRC8结果与本次数据异或
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crc = cal_crc8(crc) # 再计算CRC8
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return crc & 0xFF
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def crc16(datas):
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crc = 0xFFFF
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for pos in datas:
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crc ^= pos
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for i in range(8):
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if((crc & 1) != 0):
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crc >>= 1
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crc ^= 0xA001
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else:
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crc >>= 1
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# return ((crc & 0xff) << 8) + (crc >> 8)
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return crc
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def add8(datas):
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crc = 0x00
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for data in datas:
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crc = crc + data
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return crc&0xFF
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def checkValue_Tbus(data: bytes) -> int:
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crc = 0xFFFF
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length = len(data)
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if length % 2 != 0:
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return 0
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for i in range(0, length, 2):
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val = data[i] * 256 + data[i + 1]
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crc = crc ^ val
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return crc |