how to send Data from matlab GUI to arduino? -

i'm doing remote control using matlab gui have no experience in matlab code, not implemented :

1- arduino code ( transmitter ) :

int matlabdata; const int apin=13; const int bpin=12;  #include <virtualwire.h>  char *controller;  void setup() {    serial.begin(9600);   pinmode(apin,output);    vw_set_ptt_inverted(true); //    vw_set_tx_pin(bpin);   vw_setup(4000);// speed of data transfer kbps }   void get_action(){ if(serial.available()>0) // if there data read matlabdata=serial.read(); // read data  if(matlabdata==1){ //forward controller="f"; serial.println("forward");  }    if(matlabdata==2){ //backward controller="b"; serial.println("backward");  }   if(matlabdata==3){   //right    controller="r";   serial.println("right"); }   if(matlabdata==4){   //left    controller="l";   serial.println("left");  }   if(matlabdata==5) {   //stop    controller="s";   serial.println("stop"); } } }  void send_rf(){ vw_send((uint8_t *) controller, strlen(controller));  vw_wait_tx(); // wait until whole message gone  digitalwrite(apin,1); delay(50);   digitalwrite(apin,0);  } void loop(){ get_action(); send_rf(); //delay(1000); } 

2- matlab code "here problem" :

clear clc answer=1; % we'll store user's answer arduino=serial('com10','baudrate',9600); % create serial communication object on port com10  fopen(arduino); % initiate arduino communication  while answer fprintf(arduino,'%s',char(answer)); % send answer variable content arduino   function pushbutton1_callback(hobject, eventdata, handles)  answer= 1;  function pushbutton2_callback(hobject, eventdata, handles) answer= 2;  function pushbutton3_callback(hobject, eventdata, handles)  answer= 3;  function pushbutton4_callback(hobject, eventdata, handles) answer= 4;  function pushbutton5_callback(hobject, eventdata, handles) answer= 5;  end  fclose(arduino); % end communication arduino 

3-arduino code ( receiver) :

const int apin=13; const int bpin=12;  #include <virtualwire.h>  #include "l298_motor.h"  l298_motor l298(5,4,6,7);  void setup() {     serial.begin(9600);      l298.enable_active(11,10);   l298.enable_a('on');    l298.stop();     vw_set_ptt_inverted(true); // required dr3100     vw_set_rx_pin(bpin);     vw_setup(4000);  // bits per sec     pinmode(apin, output);      vw_rx_start();       // start receiver pll running }     void loop() {     uint8_t buf[vw_max_message_len];     uint8_t buflen = vw_max_message_len;      if (vw_get_message(buf, &buflen)) // non-blocking     {       if(buf[0]=='f'){         //forward            l298.backward(150);   //       serial.println("forward");    digitalwrite(apin,1);       }            if(buf[0]=='b'){         //backward         l298.forward(150);     //    serial.println("backward");      digitalwrite(apin,1);       }            if(buf[0]=='r'){           //right            l298.turnleft(140);       //     serial.println("right");    digitalwrite(apin,0);     }      if(buf[0]=='l'){           //left            l298.turnright(140);         //   serial.println("left");    digitalwrite(apin,0);     }    if(buf[0]=='s'){           //stop'            l298.stop();           //  serial.println("stop");    digitalwrite(apin,0);     } } } 

please ..

1- don't define callback functions inside while loop.

2- variable answer not global. can use setappdata set answer variable.

3- code sending variable answer fast possible! don't that, have use sleep(time) in while loop.

if don't need continuous data streaming, avoid while , call fprintf inside callbacks.