s=serial('​COM30','Ba​udRate',96​00); fopen(s); during interfacing matlab and 8051 uC. Unable to use com port?

Port: COM30 is not available. No ports are available. Use INSTRFIND to determine if other instrument objects are connected to the requested device. Non of the com ports are available.How to use com port for hardware interfacing ?

>> instrfind

   Instrument Object Array

   Index:    Type:     Status:   Name:  
   1         serial    closed    Serial-COM3
   2         serial    closed    Serial-COM30

>>

Answer 1

[lucky]

As I am doing this on hardware so the steps are: STEP 1. Insert your usb2RS232 Cable in your laptop(don't forget install the driver of your RS232 cable) STEP 2: Go to My computer right click on it properties -> Device manager->Ports(COM & LPS)-> there you can see the port(e.g COM7) if there is some yellow symbol it means your driver is not properly installed. So I suggest you to install it again properly. STEP 3: See the port number (COM No eg COM 7) STEP 4. go to matlab and type

s=serial('COM7','BaudRate',9600); %COM7 is your USB2RS232 COM PORT
fopen(s);
fprintf(s,'a');

PROBLEM SOLVED i am considering your have connected device and 'a' char will go to your microcontroller