Send data from MATLAB to Arduino Uno via serial communication

[lionghanwen]

Hi all, my arduino can receive the data from MATLAB. However, the arduino cannot conserve the received data. Below is my MATLAB and arduino code:

MATLAB:
arduinoCom = serial('COM6','BaudRate',9600);
sendData = 5;
fopen(arduinoCom);
fprintf(arduinoCom,'%i',sendData); %this will send 5 to the arduino
fscanf(arduinoCom);
fclose(arduinoCom);

Arduino code:
int val;
void setup() {
Serial.begin(9600);
}
void loop()
{
if (Serial.available() > 0)
{
val = Serial.read();
}
delay(100);
Serial.println(val);
}

In this case, I send a value "5" from MATLAB to arduino via serial communication. If there is no serial data from MATLAB, the value of "val" variable turn to zero. How I can conserve the "val" variable value until the next input from MATLAB. Thank you

[Railroader]

If no serial is available no Serial.read is performed and val ought to stay untouched.

What do I miss?

[Brazilino]

Hello!

Your question may be quite wide. You´ll need to be more specific.

One thing is to store "5", another thing is to store a small group of numbers (and do something with them) and a third thing is to store a large amount of data.

I suggest you taking a look at this topic that may help you on the first steps:

Serial Input Basics - updated

[groundFungus]

+1 for Robin2's serial input basics.