I am doing a project with building the GUI by Qt to input the values to Arduino, then send the signal from Arduino to Processing for imaging my signal. Is it possible? Since I am using Arduino UNO, it's only one serial port and when I open the GUI of Qt and input value, I cannot open Processing in the same time and the error is the Serial connection between Qt and Arduino. Is there any way that I can solve this problem?? Arduino Mega will be the solution??