Serialized Data Buffer

Code

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

#define START_BYTE (0xA5)
#define END_BYTE   (0x5A)

void build_packet(uint8_t command, uint16_t value, uint8_t status, uint32_t checksum) {
    uint8_t buffer[10];

    // Your logic to fill buffer
    buffer[0] =  START_BYTE;
    buffer[1] =  command;
    buffer[2] =  value       & 0xFF;
    buffer[3] = (value >> 8) & 0xFF;
    buffer[4] =  status;
    buffer[5] =  checksum & 0x000000FF;
    buffer[6] = (checksum & 0x0000FF00) >> 8;
    buffer[7] = (checksum & 0x00FF0000) >> 16;
    buffer[8] = (checksum & 0xFF000000) >> 24;
    buffer[9] =  END_BYTE;

    // Then print buffer
    for (uint8_t i = 0; i < sizeof(buffer) / sizeof(uint8_t); i++) {
        printf("%d", buffer[i]);
        
        if (i < sizeof(buffer) - 1)
            printf(" ");
    }

    printf("\n");
}

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