Sending numbers bigger than 255 from Matlab to Arduino

Using Arduino Interfacing w/ Software on the Computer
2

How about using a union?

typedef union two_byte_merge {
        struct {
                uint8_t high_byte;
                uint8_t low_byte;
        } parts;
        int16_t s_merged;
        uint16_t u_merged;
} two_byte_merge_t;

two_byte_merge_t combined;

combined.parts.high_byte = 128;
combined.parts.low_byte = 128;

printf("HB: %u\n",combined.parts.high_byte);
printf("LB: %u\n",combined.parts.low_byte);
printf("signed merged: %d\n",combined.s_merged);
printf("unsigned merged: %u\n",combined.u_merged);

Or just:

uint16_t merged = ((uint16_t)(high_byte) << 8) | (uint16_t)(low_byte);