Does Arduino sent output to TX pinout? I am beginner at Arduino,i tried to read as much as i can but i am not sure if i am doing good.I would like to send a specific code for a (non PC) device through the TX pinout when i push the button which is wired to the Pin 2.I have writtem this small code to check it:

int buttonUPpin = 2;
int UpinStatus=LOW;


void setup() {
  Serial.begin(9600);
  // put your setup code here, to run once:
pinMode(buttonUPpin, INPUT_PULLUP);  
digitalWrite(buttonUPpin,HIGH);

}

void loop() {
  // put your main code here, to run repeatedly:

UpinStatus=digitalRead(buttonUPpin);

if(LOW==UpinStatus)
{
Serial.print('A');
digitalWrite(1,LOW);

}

}


When i push the button i can see at serial monitor the 'A' character but i am not sure if this character was also sent out to the TX pinout since the TX led is not blinking only the RX led.
You haven't set pinMode for pin 1 and using pin 1 will interfere with the serial monitor (never use 0 and 1).

#define buttonUPpin = 2;
#define LedPin = 3;
int UpinStatus = LOW;


void setup()
{
    Serial.begin(9600);
    pinMode(buttonUPpin, INPUT_PULLUP);  
    pinMode(LedPin, OUTPUT);
    // digitalWrite(buttonUPpin,HIGH);  // Don't think this is right

}

void loop() 
{
    UpinStatus=digitalRead(buttonUPpin);
    if(LOW==UpinStatus)
    {
       Serial.print('A');
       digitalWrite(LedPin, LOW);  // Not sure if High or Low depends on you circuit
    }
}