Serialized Data Buffer

Code

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

void split_byte(uint8_t number_of_bytes, uint32_t reg, uint8_t* arr){
    uint32_t mask = (1<<8)-1;
    for(int i=0; i<number_of_bytes; i++){
        arr[i] = ((reg>>8*i)&mask); 
    }
}

void build_packet(uint8_t command, uint16_t value, uint8_t status, uint32_t checksum) {
    // Your logic to fill buffer
    uint8_t buffer[10];
    uint8_t value_arr[2];
    uint8_t checksum_arr[4];
    uint8_t start = 0xA5;
    uint8_t end = 0x5A;
    split_byte(2, value, value_arr);
    split_byte(4, checksum, checksum_arr);
    buffer[0] = start;
    buffer[9] = end;
    buffer[1] = command;
    buffer[2] = value_arr[0];
    buffer[3] = value_arr[1];
    buffer[4] = status;
    for(int i=0; i<4; i++){
        buffer[5+i] = checksum_arr[i];
    }
    // Then print buffer
    for(int i=0; i<10; i++){
        printf("%d ", buffer[i]);
    }
}

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