Can't turn relay 1 on/off using letter system

Hey guys !

Well, i'm trying to make a project where i can turn all the relays on and off using letter inputs via the Serial Monitor, but i can't turn the relay 1 on, all the other ones work fine.

Can you guys help me ? I'm not sure if this is a code issue or maybe i got a problem with my relay board.

Here's the code:

#define RELAY_ON 0
#define RELAY_OFF 1

#define Relay_1  1
#define Relay_2  2
#define Relay_3  3
#define Relay_4  4
#define Relay_5  5
#define Relay_6  6
#define Relay_7  7
#define Relay_8  8

int cmd;

void setup() 
{
  
  
  digitalWrite(Relay_1, RELAY_OFF);
  digitalWrite(Relay_2, RELAY_OFF);
  digitalWrite(Relay_3, RELAY_OFF);
  digitalWrite(Relay_4, RELAY_OFF);
  digitalWrite(Relay_5, RELAY_OFF);
  digitalWrite(Relay_6, RELAY_OFF);
  digitalWrite(Relay_7, RELAY_OFF);
  digitalWrite(Relay_8, RELAY_OFF);
  
  pinMode(Relay_1, OUTPUT);
  pinMode(Relay_2, OUTPUT);
  pinMode(Relay_3, OUTPUT);
  pinMode(Relay_4, OUTPUT);
  pinMode(Relay_5, OUTPUT);
  pinMode(Relay_6, OUTPUT);
  pinMode(Relay_7, OUTPUT);
  pinMode(Relay_8, OUTPUT);
  
  Serial.begin(9600);
}
  
  void loop()
  {
    
    cmd = Serial.read();
    
    
    
    // LIGANDO O RELAY 1.
    
    
    
    if (cmd == 'A') {
      
    digitalWrite(Relay_1, RELAY_ON);
    
    } 
    
    
    
    // DESLIGANDO O RELAY 1.
    
    
    
    if (cmd == 'B') {
      
      digitalWrite(Relay_1, RELAY_OFF);
      
    }
    
    
    
    //LIGANDO O RELAY 2.
    
    
    
    if (cmd == 'C') {
      
      digitalWrite(Relay_2, RELAY_ON);
      
    }
    
    
    
    //DESLIGANDO O RELAY 2.
    
    
    
    if (cmd == 'D') {
      
      digitalWrite(Relay_2, RELAY_OFF);
      
    }
    
    
    
    //LIGANDO O RELAY 3.
    
    
    
    if (cmd == 'E') {
      
      digitalWrite(Relay_3, RELAY_ON);
      
    }
    
    
    //DESLIGANDO O RELAY 3.
    
    
    
    if (cmd == 'F') {
      
      digitalWrite(Relay_3, RELAY_OFF);
      
    }
    
    
    
    //LIGANDO O RELAY 4.
    
    
    
    if (cmd == 'G') {
      
      digitalWrite(Relay_4, RELAY_ON);
      
    }
    
    
    
    //DESLIGANDO O RELAY 4.
    
    
    
    if (cmd == 'H') {
      
      digitalWrite(Relay_4, RELAY_OFF);
      
    }
    
    
    
    //LIGANDO O RELAY 5.
    
    
    
    if (cmd == 'I') {
      
      digitalWrite(Relay_5, RELAY_ON);
      
    }
    
    
    
    //DESLIGANDO O RELAY 5.
    
    
    
    if (cmd == 'J') {
      
      digitalWrite(Relay_5, RELAY_OFF);
      
    }
    
    
    
    //LIGANDO O RELAY 6.
    
    
    
    if (cmd == 'K') {
      
      digitalWrite(Relay_6, RELAY_ON);
      
    }
    
    
    
    //DESLIGANDO O RELAY 6.
    
    
    
    if (cmd == 'L') {
      
      digitalWrite(Relay_6, RELAY_OFF);
      
    }
    
    
    
    //LIGANDO O RELAY 7.
    
    
    
    if (cmd == 'M') {
      
      digitalWrite(Relay_7, RELAY_ON);
    
    }
    
    
    
    //DESLIGANDO O RELAY 7.
    
    
    
    if (cmd == 'N') {
      
      digitalWrite(Relay_7, RELAY_OFF);
      
    }
    
    
    
    //LIGANDO O RELAY 8.
    
    
    
    if (cmd == 'O') {
      
      digitalWrite(Relay_8, RELAY_ON);
      
      
      
    }
    
    
    
    //DESLIGANDO O RELAY 8.
    
    
    
    if (cmd == 'P') {
      
      digitalWrite(Relay_8, RELAY_OFF);
      
    }
    
  }

So , do you guys know if i'm making a code mistake ?

PS: When i use this code the relay 1 works fine:

#define RELAY_ON 0
#define RELAY_OFF 1
/*-----( Declare objects )-----*/
/*-----( Declare Variables )-----*/
#define Relay_1  1  // Arduino Digital I/O pin number
#define Relay_2  2
#define Relay_3  3
#define Relay_4  4
#define Relay_5  5
#define Relay_6  6
#define Relay_7  7
#define Relay_8  8

void setup()   /****** SETUP: RUNS ONCE ******/
{
//-------( Initialize Pins so relays are inactive at reset)----
  digitalWrite(Relay_1, RELAY_OFF);
  digitalWrite(Relay_2, RELAY_OFF);
  digitalWrite(Relay_3, RELAY_OFF);
  digitalWrite(Relay_4, RELAY_OFF);  
  digitalWrite(Relay_5, RELAY_OFF);
  digitalWrite(Relay_6, RELAY_OFF);
  digitalWrite(Relay_7, RELAY_OFF);
  digitalWrite(Relay_8, RELAY_OFF);
  
//---( THEN set pins as outputs )----  
  pinMode(Relay_1, OUTPUT);   
  pinMode(Relay_2, OUTPUT);  
  pinMode(Relay_3, OUTPUT);  
  pinMode(Relay_4, OUTPUT);
  pinMode(Relay_5, OUTPUT);   
  pinMode(Relay_6, OUTPUT);  
  pinMode(Relay_7, OUTPUT);  
  pinMode(Relay_8, OUTPUT);  
  delay(4000); //Check that all relays are inactive at Reset

}//--(end setup )---


void loop()   /****** LOOP: RUNS CONSTANTLY ******/
{
//---( Turn all 4 relays ON in sequence)---
  digitalWrite(Relay_1, RELAY_ON);// set the Relay ON
  delay(1000);              // wait for a second
  digitalWrite(Relay_2, RELAY_ON);// set the Relay ON
  delay(1000);              // wait for a second  
  digitalWrite(Relay_3, RELAY_ON);// set the Relay ON
  delay(1000);              // wait for a second
  digitalWrite(Relay_4, RELAY_ON);// set the Relay ON
  delay(1000);              // wait see all relays ON
  digitalWrite(Relay_5, RELAY_ON);// set the Relay ON
  delay(1000);              // wait for a second
  digitalWrite(Relay_6, RELAY_ON);// set the Relay ON
  delay(1000);              // wait for a second  
  digitalWrite(Relay_7, RELAY_ON);// set the Relay ON
  delay(1000);              // wait for a second
  digitalWrite(Relay_8, RELAY_ON);// set the Relay ON
  delay(4000);
  
//---( Turn all 4 relays OFF in sequence)---  
  digitalWrite(Relay_1, RELAY_OFF);// set the Relay OFF
  delay(1000);              // wait for a second
  digitalWrite(Relay_2, RELAY_OFF);// set the Relay OFF
  delay(1000);              // wait for a second  
  digitalWrite(Relay_3, RELAY_OFF);// set the Relay OFF
  delay(1000);              // wait for a second
  digitalWrite(Relay_4, RELAY_OFF);// set the Relay OFF
  delay(1000);              // wait see all relays OFF  
  digitalWrite(Relay_5, RELAY_OFF);// set the Relay OFF
  delay(1000);              // wait for a second
  digitalWrite(Relay_6, RELAY_OFF);// set the Relay OFF
  delay(1000);              // wait for a second  
  digitalWrite(Relay_7, RELAY_OFF);// set the Relay OFF
  delay(1000);              // wait for a second
  digitalWrite(Relay_8, RELAY_OFF);// set the Relay OFF
  delay(4000);
  
}

Sorry if i posted this in the wrong section of the forum, and also for my bad english (I'm from Brazil =P)

You're using Serial which uses pins 0 and 1, which clashes with your use of pin one for relay_1.

So where should i put Relay_1 ? Can i connect pin 9 to Relay 1 and do this:

#define RELAY_ON 0
#define RELAY_OFF 1

#define Relay_1 9

(...)

If i do this would the relay 1 turn on ?

Don't worry, i've got it to work using the code above.

Thanks for the help friend !