round() returns a double which cannot be used with logical operator &. Please check if this doesn't have side effects, as I am not fluent in C++ nor in knxtpuart.
I´ve just merged another commit which did fixed the same error but differently than you.
Can you check if this is working for you? (there was also a 2nd fix done)
round() returns a double which cannot be used with logical operator &. Please check if this doesn't have side effects, as I am not fluent in C++ nor in knxtpuart.