No, DataReceived Event will be fired when (every time) the PC-side serial interface receives data. The PC (your C# program) sends data to the Board, the board then replies to the PC, that's when DataReceived will fire. As far as I can see, you are missing the Baudrate, so when the PC sends data to the board, the Board is not understanding the message, thus it never replies and DataReceived is never fired.

What you should include in the button1_Click event is:

serialPort1.Baudrate = 9600? 14400? What is the Board expecting?