How to Control Arduino with MATLAB

How can I control digital inputs on an Arduino using MATLAB?

Here is a hello world~ of serial communication between MATLAB and Arduino. This communication will be utilized for switching the states of digital outputs in Arduino UNO. This is a pretty generic method and will work for other micro controllers of the same family. Arduino UNO has only one port for serial communication.

What the heck is a Serial Port?

A serial port is a data communication channel where 1 bit at a time is transferred.

Why do we need Serial Ports?

Serial port handles communication between connected devices . Today nearly every IoT works due to serial ports.

How does it work?

Sending character S via Serial Port

In serial communication the receiver sends a character (say ‘s’) by converting the character to it’s binary code ( 01110011 ). The converted character is transmitted via Serial Port from transmitter to receiver via fluctuations in the voltage.

Getting Started

• Connect Arduino UNO to the laptop.

• Write/paste the following code.

Arduino

Methods

Serial.begin(9600)

It opens serial port with 9600 bauds (data transfer rate).

Serial.available

Check if data is received from computer.

digitalWrite(5, HIGH);

Turn on pin 5 on Arduino UNO.

Arduino Program

int incomingByte = 0;
void setup() {
  Serial.begin(9600);
  for (int i=5; i<=12; i++){
    pinMode(i, OUTPUT);
  }
}

void loop() {
  if (Serial.available() > 0){
    incomingByte = Serial.read();
    Serial.println(incomingByte);
    switch (incomingByte){
     case 0:
      digitalWrite(5, LOW);
      break;
     case 1:
      digitalWrite(5, HIGH);
      break;
      ///////////////////////   
     case 2:
      digitalWrite(6, LOW);
      break;
     case 3:
      digitalWrite(6, HIGH);
      break; 
     ///////////////////////
    case 4:
      digitalWrite(7, LOW);
      break;
    case 5:
      digitalWrite(7, HIGH);
      break; 
     ///////////////////////
     case 6:
      digitalWrite(8, LOW);
      break;
     case 7:
      digitalWrite(8, HIGH);
      break; 
     ///////////////////////
    case 8:
      digitalWrite(9, LOW);
      break;
    case 9:
      digitalWrite(9, HIGH);
      break; 
     ///////////////////////
    case 10:
      digitalWrite(10, LOW);
      break;
    case 11:
      digitalWrite(10, HIGH);
      break; 
     ///////////////////////
    case 12:
      digitalWrite(11, LOW);
      break;
    case 13:
      digitalWrite(11, HIGH);
      break; 
     ///////////////////////
    case 14:
      digitalWrite(12, LOW);
      break;
    case 15:
      digitalWrite(12, HIGH);
      break; 
     ///////////////////////
  }
}
}

• Compile & Upload.

MATLAB Side

• Open MATLAB and copy this program

%MATLAB Code for Serial Communication with Arduinofclose(instrfind);
delete(instrfind);
x=serial('COM5','BaudRate', 9600);
fopen(x)
go = true;while go

a = input('Enter 1 to turn ON LED & 0 to turn OFF or 2 to exit, press: ');
fwrite(x, a, 'char'); 
if (a == 2)
  go=false;
end
end
fclose(x)fclose(x)