Validate Frame Size

Question

Problem: Validate Frame Size. Solve this hands-on electronics task on EWskills.

Accepted Answer

#include 
#include 
using namespace std;
 
// Protocol frame used for sensor communication
struct Frame {
    uint16_t header;      // 2 bytes
    uint8_t  command;     // 1 byte
    uint8_t  length;      // 1 byte
    uint8_t  payload[6];  // 6 bytes
    uint16_t checksum;    // 2 bytes
};
 
// Validate compile-time size
static_assert(sizeof(Frame) == 12, "Frame size mismatch");
 
int main() {
    cout << "Frame OK";
    return 0;
}

Explanation & Logic Summary:

The struct must match the protocol exactly: 12 bytes total.
Any mistake in layout changes sizeof(Frame) and causes compilation failure.
static_assert enforces correctness at compile time, not runtime.
This prevents silent packet corruption and protocol mismatches.

Firmware Relevance & Real Embedded Context:

This problem mirrors real firmware practices:

UART packet formats
BLE advertisement frames
CAN message structures
Sensor communication packets
Bootloader frame formats
Diagnostic protocol frames

Static assertions protect against:

Accidental structural changes
Compiler padding issues
Protocol drift between teams
Hard-to-debug communication failures

This is a canonical embedded C++ safety pattern used in production firmware.

69. Validate Frame Size