Counter Up Arduino Bluetooth

About Counter Up Arduino Bluetooth

Wiring
Arduino With IR Obstacle
PIN 7 ---------------Out
5V ----------------5V
GND ---------------GND

Arduino With Bluetooth HC05
Tx----------------Rx
Rx----------------Tx
5V----------------5V
GND---------------GND

Sketch Arduino
int n ;
void setup() {
pinMode(7,INPUT);
Serial.begin(9600);
}
void loop() {

if (digitalRead(7) == LOW) {
n ++;
Serial.print(n);
delay(1000);
}
}