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[on:]

Hi,
I want to interface MATLAB with Arduino MEGA.
For the serial reading operation from Arduino MEGA to MATLAB i havn't any problem.

But I don't succeed for the writing operation from MATLAB to Arduino MEGA, this is my code:


Arduino Code:

byte incomingByte = 0;      

void setup()
{
      Serial.begin(9600);
}

void loop() {
      
      if (Serial.available() > 0)
       {
                incomingByte = Serial.read();
            Serial.print("I received: ");
            Serial.println(incomingByte, DEC);
            
       }
}


MATLAB code:

function serialMTOA()

s = serial('COM5', 'BaudRate', 9600);
set(s,'DataBits',8);
set(s,'StopBits',1);
set(s,'Parity','none');

fopen(s);

fwrite(s, 5,'uint8','async');

stopasync(s);
fclose(s);

end



Are there some errors?
When I send the Matlab function I see that Arduino receives (TX led blinks) but when I try to see the Arduino Serial Monitor there's nothing.

Others informations: I use the usb alimentation, and only the usb as serial (no others comunication ports).

[Reply #1 on:]

hm

is it possible to write to the arduino with one program and to read from it with another program?

what happens when u make the arduino turning on pin 13 if it receives an 'A' and off if it receives an 'E'...?

-arne

[Reply #2 on:]

I get round this by getting matlab to check the connection status first:

Comtest = arduino.TransferStatus; % check port status before trying to write
    if Comtest(1) == 'i';
            fwrite(arduino, ServoValue, 'uint8','async')
    else
        Comtest;
        pause(0.08)
    end

Hope this helps

[Reply #3 on:]

'i' here as in idle