Hello, I'm a computer engineering student, working on my senior design project. In my project we are designing a medical monitoring device using an embedded system. In addition to that, we will be using MATLAB to take in the readings and do some analysis and graphing. I'm using RS232 or serial communication between MATLAB and the Handy Board(HC11). I know that in order to initiate the communication i need to open my serial port using the commands: s = serial('COM1') fopen(s) However, everytime i run the code it gives me a problem with "fopen(s)". I have checked the baud rate its fixed at 9600. I have also checked the status of my ports and it says none of them is open. My handy Board is running properly, but my pc or MATLAB doesn't seem to recognize any connection. I tried connecting another device with MATLAB and it functioned properly, so what could be the problem with the handy board??? May anyone help please!!