Serialized Data Buffer

Code

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

typedef union{
    uint32_t checksum_v;
    uint8_t checksum_char[4];
}CK_CHAR;

typedef union{
    uint16_t valI;
    uint8_t val_i[2];
}val_I;

void build_packet(uint8_t command, uint16_t value, uint8_t status, uint32_t checksum) {
    uint8_t buffer[10];
     // Your logic to fill buffer
    CK_CHAR cc;
    val_I v;
    v.valI = value;

    cc.checksum_v = checksum;
    *(buffer + 0) = 0xA5;
    *(buffer + 1) = command;
    *(buffer + 2) = v.val_i[0];
    *(buffer + 3) = v.val_i[1];
    *(buffer + 4) = status;

    *(buffer + 5) = cc.checksum_char[0];
    *(buffer + 6) = cc.checksum_char[1];
    *(buffer + 7) = cc.checksum_char[2];
    *(buffer + 8) = cc.checksum_char[3];
    *(buffer + 9) = 0x5A;   
    // Then print buffer
    for(int i = 0 ; i < 10; i++){
        printf("%hu", buffer[i]);
        if(i != 9){
            printf(" ");
        }
    }
}

int main() {
    uint8_t cmd, status;
    uint16_t val;
    uint32_t crc;

    scanf("%hhu %hu %hhu %u", &cmd, &val, &status, &crc);
    build_packet(cmd, val, status, crc);
    return 0;
}

Solving Approach