45. Serialized Data Buffer

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

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

    // Use bit manipulation 

    buffer[0] = 0xA5;             // Start byte
    buffer[1] = command;          // Command

    // Fill value (2 bytes)
    for(int i = 0; i < 2; i++)
        buffer[2+i] = (value >> (8*i)) & 0xFF;

    buffer[4] = status;           // Status

    // Fill checksum (4 bytes)
    for(int i = 0; i < 4; i++)
        buffer[5+i] = (checksum >> (8*i)) & 0xFF;

    buffer[9] = 0x5A;             // End byte

    // Print the entire buffer contents as space-separated integers
    for(int i = 0; i < 10; i++){
        printf("%u ", 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;
}