This shows 0x8000:
byte b = 0x80;
unsigned long ul = 256;
unsigned long r = b * ul;
Serial.println(r, HEX);
So it appears that what dc42 said is correct (the second quote, about the shift operations).
This shows 0x8000:
byte b = 0x80;
unsigned long ul = 256;
unsigned long r = b * ul;
Serial.println(r, HEX);
So it appears that what dc42 said is correct (the second quote, about the shift operations).