How to make bluetooth control relays system at home | DIY

[@GADGETPODDAofficial]

/*
Gadget Podda
Bluetooth 5 relays control
*/
char val;
int relay1 = 2;
int relay2 = 3;
int relay3 = 4;
int relay4 = 5;
int relay5 = 6;
void setup() {
pinMode(relay1, OUTPUT);
pinMode(relay2, OUTPUT);
pinMode(relay3, OUTPUT);
pinMode(relay4, OUTPUT);
pinMode(relay5, OUTPUT);
Serial.begin(9600);
}
void loop() {
if (Serial.available()) {
val = Serial.read();
Serial.println(val);
}
if (val == '0') {
digitalWrite(relay1, HIGH);
} else if (val == '1') {
digitalWrite(relay1, LOW);
}
if (val == '2') {
digitalWrite(relay2, HIGH);
} else if (val == '3') {
digitalWrite(relay2, LOW);
}
if (val == '4') {
digitalWrite(relay3, HIGH);
} else if (val == '5') {
digitalWrite(relay3, LOW);
}
if (val == '6') {
digitalWrite(relay4, HIGH);
} else if (val == '7') {
digitalWrite(relay4, LOW);
}
if (val == '8') {
digitalWrite(relay4, HIGH);
} else if (val == '9') {
digitalWrite(relay4, LOW);
}
if (val == 'a') {
digitalWrite(relay5, HIGH);
} else if (val == 'b') {
digitalWrite(relay5, LOW);
}
if (val == 'c') {
digitalWrite(relay1, HIGH);
digitalWrite(relay2, HIGH);
digitalWrite(relay3, HIGH);
digitalWrite(relay4, HIGH);
digitalWrite(relay5, HIGH);
} else if (val == 'd') {
digitalWrite(relay1, LOW);
digitalWrite(relay2, LOW);
digitalWrite(relay3, LOW);
digitalWrite(relay4, LOW);
digitalWrite(relay5, LOW);
}
}