@TomHoe said in Int16 to QByteArray: didn't knew that '!' is the same as 0x21.. See http://www.ascii-code.com/ '!' == 33 == 0x21 == 0b00100001 @TomHoe said in Int16 to QByteArray: Is there a way to rewrite it to regular hex codes ? Or does every controller understand this notation ? Again, '!' == 33 == 0x21 == 0b00100001 Those are different ways of displaying the same bytes. The controller does not see any "hex" or "notation"; it only sees the sequence of 0's and 1's. I recommend you learn about how bits/bytes are stored in computer memory: http://statmath.wu.ac.at/courses/data-analysis/itdtHTML/node55.html

Hi, Are you also using g++4.9 to build Qt ?