Created
July 23, 2018 15:09
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#include <stdio.h> | |
#include <stdint.h> | |
uint16_t crc16modbus(uint8_t *data, uint16_t len) | |
{ | |
uint16_t poly = 0xA001; | |
uint16_t crc = 0xffff; | |
uint8_t *ptr = data; | |
while(len--) | |
{ | |
crc ^= (0xFF & *ptr++); | |
for (uint8_t i = 0 ; i < 8 ; i++) | |
{ | |
if (crc & 0x0001) | |
crc = ((crc >> 1) & 0xFFFF) ^ poly; | |
else | |
crc = ((crc >> 1) & 0xFFFF); | |
} | |
} | |
return crc; | |
} | |
int main(int argc, char *argv[]) | |
{ | |
uint8_t instr[]={0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39 }; | |
printf("CRC: 0x%04x\n", crc16modbus(instr, sizeof(instr))); | |
return 0; | |
} |
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