My project is AVR Based Temperature Controller.

I'm using serial communication for interfacing the hardware with Matlab Simulink. I'm suppose to Receive & Transmit the data, but I'm only able to receive it, while transmitting simulink shows some error.

    function
  temp_val=Serial_out(Temp_val)

% portno = input('Port No = ');

% if portno==1

% Port = 'COM1'

% else

% display('Use 1 for Com1 port');

% end

s = serial(
'COM1','BaudRate',4800,'DataBits',8);

fopen(s)

%A=[34,0]

c_data(1)=mod(Temp_val,10)

c_data(2) = c_data(1)+48;

c_data(2)=(Temp_val-c_data(1))/10

c_data(2) = c_data(2)+48;

c_data=Temp_val

%temp_str = num2str(c_data);

c_data=c_data'

%c_data = circshift(c_data,1)

c_data = Temp_val;

fprintf(s,'%d',c_data)

fclose(s)

% clear s

[Walter Roberson]

What error is shown?