I wrote a serial protocol to exchange data between MCU and a PC.
This protocol provides a checksum to verify data integrity.
At the moment I use a simple sum of each byte but I think that the use of CRC peripheral could be an improvements.
Unfortunately the CRC peripheral requires a uint32_t buffer but my payload is an uint8_t.
Casting the uint8_t to uint32_t is a problem because the CRC will be wrong because on the PC side.
I computed the CRC as byte (from serial interface) but I computed the CRC on MCU as word (due to cast uint8_t to uint32_t ).
/* This is my packet structure */
typedef struct PROTOCOL_Packet
/* This is my routine to compute the CRC: */
if( CRC_Calculate( (uint32_t*)pkt->payload.bytes, (uint32_t)(*pkt).length, &pkt->checksum ) == APP_TRUE )
SERIAL_Write( (uint8_t*)pkt, pkt->length + 7 );
/* Where CRC_Calculate is: */
uint8_t CRC_Calculate( uint32_t* buffer, uint32_t bufferLen, OUT uint32_t* crc32)
*crc32 = HAL_CRC_Calculate( &hcrc, buffer, (bufferLen/4) );
I can't change the type of my payload to uint32_t because on the PC side I want to avoid byte manipulation to retrieve the uint32_t back from bytes.
Thanks in advance