#include <stdio.h>
#include <stdint.h>
typedef struct {
uint8_t start;
uint8_t command;
uint16_t data;
uint8_t crc;
uint8_t end;
} Packet;
void print_packet_fields(uint8_t *buffer) {
// Overlay struct and print values
Packet packet;
packet.start = buffer[0];
packet.command = buffer[1];
packet.data = buffer[2];
packet.data += buffer[3] << 8;
packet.crc = buffer[4];
packet.end = buffer[5];
printf("Start: %d\n", packet.start);
printf("Command: %d\n", packet.command);
printf("Data: %d\n", packet.data);
printf("CRC: %d\n", packet.crc);
printf("End: %d\n", packet.end);
}
int main() {
uint8_t buffer[6];
for (int i = 0; i < 6; i++) {
scanf("%hhu", &buffer[i]);
}
print_packet_fields(buffer);
return 0;
}
/*
buffer as an input
populate the packet structure with the items of buffer
How is the data updated ?
buffer[0] = packet.start;
buffer[1] = packet.command;
buffer[2] = packet.data;
buffer[3] << 8 = packet.start;
buffer[4] = packet.crc;
buffer[5] = packet.end;
packet.data = buffer[2];
packet.data += buffer[3] << 8 // add sequentially
*/
Input
165 1 52 18 119 90
Expected Output
Start: 165 Command: 1 Data: 4660 CRC: 119 End: 90