Serialized Data Buffer

Code

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

typedef struct {
        uint8_t start;
        uint8_t command;
        uint16_t value;
        uint8_t status;
        uint32_t crc;
        uint8_t end;
} UART_t;


void build_packet(uint8_t command, uint16_t value, uint8_t status, uint32_t checksum) {
    uint8_t buf[10];
    uint8_t i;
    // Your logic to fill buffer
    // Then print buffer
    buf[0] = 0xA5;
    buf[1] = command;
    buf[2] = value & 0xFF;
    buf[3] = (value >> 8) & 0xFF;
    buf[4] = status;
    buf[5] = (checksum & 0xFF);
    buf[6] = (checksum >> 8) & 0xFF;
    buf[7] = (checksum >> 16) & 0xFF;
    buf[8] = (checksum >> 24) & 0xFF;
    buf[9] = 0x5A; 
    for (i=0; i < 10; i++)
        printf("%hu ", buf[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

Shift the eentities larger than uint8_t and mask higher bits to store it in the uint8_t array