79. Extract Packet Fields from Byte Stream

#include <stdio.h>
#include <stdint.h>

typedef struct {
    uint8_t start;
    uint8_t command;
    uint16_t data;
    uint8_t crc;
    uint8_t end;
} Packet;
Packet pack;
void print_packet_fields(uint8_t *buffer) {
    pack.start=*(buffer);
    pack.command=*(buffer+1);
    //((*(buffer+3))<<8)+*(buffer+2)
    pack.data=((*(buffer+3))<<8)+(*(buffer+2));
    pack.crc=*(buffer+4);
    pack.end=*(buffer+5);
    printf("Start: %d\n",pack.start);
    printf("Command: %d\n",pack.command);
    printf("Data: %d\n",pack.data);
    printf("CRC: %d\n",pack.crc);
    printf("End: %d",pack.end);
    // Overlay struct and print values
}

int main() {
    uint8_t buffer[6];
    for (int i = 0; i < 6; i++) {
        scanf("%hhu", &buffer[i]);
    }
    print_packet_fields(buffer);
    return 0;
}

+ has higher precedence that << make sure it is always in brackets

void print_packet_fields(uint8_t *buffer) {
    // Overlay buffer with Packet struct
    Packet *pkt = (Packet *)buffer;

    printf("Start: %u\n", pkt->start);
    printf("Command: %u\n", pkt->command);
    printf("Data: %u\n", pkt->data);
    printf("CRC: %u\n", pkt->crc);
    printf("End: %u", pkt->end);
}

this should be used