Packet Layout Using Union with Struct

Code

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

typedef union {
    struct {
        uint8_t start;
        uint8_t command;
        uint16_t data;
        uint8_t crc;
        uint8_t end;
    } fields;
    uint8_t raw[6];
} Packet;

void build_and_print_packet(uint8_t s, uint8_t c, uint16_t d, uint8_t crc, uint8_t e) {
    Packet pac;

    // Fillup fields
    pac.fields = {
        .start = s,
        .command = c,
        .data = d,
        .crc = crc,
        .end = e
    };

    // Print raw packet
    for (uint8_t i = 0; i < sizeof(pac); i++) {
        printf("%u", pac.raw[i]);

        if (i < sizeof(pac) - 1) {
            printf(" ");
        }
    }

    printf("\n");
}

int main() {
    uint8_t s, c, crc, e;
    uint16_t d;
    scanf("%hhu %hhu %hu %hhu %hhu", &s, &c, &d, &crc, &e);
    build_and_print_packet(s, c, d, crc, e);
    return 0;
}

Solving Approach