What should i write in this code to Turn ON/OFF a LED?

Hello everyone! I found this application and skeletal code. I want to use it for a home automation project for school. i don't know what to write in 2a) section to turn ON/OFF a LED (STEP 6 on the below link). I wrote: if (pin_value=HIGH) { digitalWrite (13, HIGH); } and didn't works, i wrote just DigitalWrite (13, HIGH); and didn;t work also.

i've made the circuit diagram like in the below link. Thank you very much!

http://www.instructables.com/id/Andruino-A-Simple-2-Way-Bluetooth-based-Android-C/

Because "=" is not the same thing as "==".

I put == in 2 ways:

if (pin_value==HIGH) { digitalWrite (13, HIGH); } and if (pin_value== '1') { digitalWrite (13, 1); }

I don't understood why is not working. Thank you!

That's not what you posted above. Please post your entire actual sketch, in code tags so it is easier to read.

Here is the entire code.

/*
 PROJECT: ArduDroid 
 PROGRAMMER: Hazim Bitar (techbitar at gmail dot com)
 DATE: Oct 31, 2013
 FILE: ardudroid.ino
 LICENSE: Public domain
*/

#define START_CMD_CHAR '*'
#define END_CMD_CHAR '#'
#define DIV_CMD_CHAR '|'
#define CMD_DIGITALWRITE 10
#define CMD_ANALOGWRITE 11
#define CMD_TEXT 12
#define CMD_READ_ARDUDROID 13
#define MAX_COMMAND 20  // max command number code. used for error checking.
#define MIN_COMMAND 10  // minimum command number code. used for error checking. 
#define IN_STRING_LENGHT 40
#define MAX_ANALOGWRITE 255
#define PIN_HIGH 3
#define PIN_LOW 2

String inText;

void setup() {
  Serial.begin(9600);
  Serial.println("ArduDroid 0.12 Alpha by TechBitar (2013)");
  Serial.flush();
}

void loop()
{
  Serial.flush();
  int ard_command = 0;
  int pin_num = 0;
  int pin_value = 0;

  char get_char = ' ';  //read serial

  // wait for incoming data
  if (Serial.available() < 1) return; // if serial empty, return to loop().

  // parse incoming command start flag 
  get_char = Serial.read();
  if (get_char != START_CMD_CHAR) return; // if no command start flag, return to loop().

  // parse incoming command type
  ard_command = Serial.parseInt(); // read the command
  
  // parse incoming pin# and value  
  pin_num = Serial.parseInt(); // read the pin
  pin_value = Serial.parseInt();  // read the value

  // 1) GET TEXT COMMAND FROM ARDUDROID
  if (ard_command == CMD_TEXT){   
    inText =""; //clears variable for new input   
    while (Serial.available())  {
      char c = Serial.read();  //gets one byte from serial buffer
      delay(5);
      if (c == END_CMD_CHAR) { // if we the complete string has been read
        // add your code here
        break;
      }              
      else {
        if (c !=  DIV_CMD_CHAR) {
          inText += c; 
          delay(5);
        }
      }
    }
  }

  // 2) GET digitalWrite DATA FROM ARDUDROID
  if (ard_command == CMD_DIGITALWRITE){  
    if (pin_value == PIN_LOW) pin_value = LOW;
    else if (pin_value == PIN_HIGH) pin_value = HIGH;
    else return; // error in pin value. return. 
    set_digitalwrite( pin_num,  pin_value);  // Uncomment this function if you wish to use 
    return;  // return from start of loop()
  }

  // 3) GET analogWrite DATA FROM ARDUDROID
  if (ard_command == CMD_ANALOGWRITE) {  
    analogWrite(  pin_num, pin_value ); 
    // add your code here
    return;  // Done. return to loop();
  }

  // 4) SEND DATA TO ARDUDROID
  if (ard_command == CMD_READ_ARDUDROID) { 
    // char send_to_android[] = "Place your text here." ;
    // Serial.println(send_to_android);   // Example: Sending text
    Serial.print(" Analog 0 = "); 
    Serial.println(analogRead(A0));  // Example: Read and send Analog pin value to Arduino
    return;  // Done. return to loop();
  }
}

// 2a) select the requested pin# for DigitalWrite action
void set_digitalwrite(int pin_num, int pin_value)
{
  switch (pin_num) {
  case 13:
    pinMode(13, OUTPUT);
    if( pin_value == HIGH){
    digitalWrite(13, HIGH);  
    }
    break;
    
  case 12:
    pinMode(12, OUTPUT);
    digitalWrite(12, pin_value);   
     
          digitalWrite (12, HIGH);
          
       
    break;
  case 11:
    pinMode(11, OUTPUT);
    digitalWrite(11, pin_value);         
    // add your code here 
    break;
  case 10:
    pinMode(10, OUTPUT);
    digitalWrite(10, pin_value);         
    // add your code here 
    break;
  case 9:
    pinMode(9, OUTPUT);
    digitalWrite(9, pin_value);         
    // add your code here 
    break;
  case 8:
    pinMode(8, OUTPUT);
    digitalWrite(8, pin_value);         
    // add your code here 
    break;
  case 7:
    pinMode(7, OUTPUT);
    digitalWrite(7, pin_value);         
    // add your code here 
    break;
  case 6:
    pinMode(6, OUTPUT);
    digitalWrite(6, pin_value);         
    // add your code here 
    break;
  case 5:
    pinMode(5, OUTPUT);
    digitalWrite(5, pin_value); 
    // add your code here       
    break;
  case 4:
    pinMode(4, OUTPUT);
    digitalWrite(4, pin_value);         
    // add your code here 
    break;
  case 3:
    pinMode(3, OUTPUT);
    digitalWrite(3, pin_value);         
    if( pin_value == '1'){
    digitalWrite(3, pin_value);  
    }
    break;
  case 2:
    pinMode(2, OUTPUT);
    digitalWrite(2, pin_value); 
    digitalWrite (2,pin_value);    
    break;      
    // default: 
    // if nothing else matches, do the default
    // default is optional
  } 
}

i have made changes only here

// 2a) select the requested pin# for DigitalWrite action
void set_digitalwrite(int pin_num, int pin_value)
{
  switch (pin_num) {
  case 13:
    pinMode(13, OUTPUT);
    if( pin_value == HIGH){
    digitalWrite(13, HIGH);  
    }
    break;
    
  case 12:
    pinMode(12, OUTPUT);
    digitalWrite(12, pin_value);   
     
          digitalWrite (12, HIGH);
          
       
    break;

What is wrong with using the code from the instructable? It’s already there, ready to use:

// 2a) select the requested pin# for DigitalWrite action
void set_digitalwrite(int pin_num, int pin_value)
{
  switch (pin_num) {
  case 13:
    pinMode(13, OUTPUT);
    digitalWrite(13, pin_value); 
    // add your code here     
    break;

Thank you very much for spending time with me.

I don't know what's happend. I can't give commands from my Android (i use them app). i have made the circuit like in thei diagram. Maybe is something about my Bluetooth Module (is an HC-05). I can use this module with another app's.

Again, thank you very much!

You better start with a small code, say on/off Pin 13. Instead of dealing with a very lengthy code. May be check one of my post explains about Bluetooth communication.

I used Software Serial to communicate with BT Module. So that I can monitor the communication using Serial monitor in Arduino IDE.

You can totally ignore the writeAck() in that post.

So let me get this straight. The OP wants to do home automation, Android, Bluetooth, Arduino and C, but cannot debug and cannot even turn an LED on. The wiring diagram / schematic is missing too. This is too much too fast. The OP should start MUCH simpler.

Good Luck!