CODE WITH LIMITLESS

  #define  trigPin  9 #define  echoPin  8 #define  Buzzer1  5 //active int  sound =  250 ; void   setup () {   Serial . begin  ( 9600 );   pinMode (trigPin, OUTPUT);   pinMode (echoPin, INPUT);   pinMode (Buzzer1, OUTPUT); } void   loop () {    Serial . begin ( 9600 );    long  duration, distance;    digitalWrite (trigPin, LOW);    delay ( 2 );    digitalWrite (trigPin, HIGH);    delay ( 10 );    digitalWrite (trigPin, LOW);   duration =  pulseIn (echoPin, HIGH);   distance = (duration/ 2 ) /  29.1 ;    digitalWrite (Buzzer1, LOW);    if  (distance< 20 ) {      digitalWrite (Buzzer1, HIGH);      delay ( 2000 );   }    if  (di...

 #include <LiquidCrystal.h> LiquidCrystal lcd(12,11,5,4,3,2); #define trigPin = 7; #define echoPin = 6; void setup(){ Serial.begin(9600); pinMode(trigPin, OUTPUT);  pinMode(echoPin, INPUT); lcd.begin(16,2) } void loop() { digitalWrite(trigPin, LOW); delayMicroseconds(2); digitalWrite(trigPin, HIGH); delayMicroseconds(10); digitalWrite(trigPin, LOW); duration = pulseIn(echoPin, HIGH); distance= (duration/2)/29.1; Serial.print(distance); lcd.print(Distance); lcd.println("cm"); delay(500); }

 const int NbrLEDs = 8;  const int ledPins[] = {5, 6, 7, 8, 9, 10, 11};  const int photocellPin = A0;  int sensorValue = 0; // value read from the sensor  int ledLevel = 0; // sensor value converted into LED 'bars'  void setup()  { for (int led = 0; led < NbrLEDs; led++) { pinMode(ledPins[led], OUTPUT);// make all the LED pins outputs  }  }  void loop() { sensorValue = analogRead(photocellPin); ledLevel = map(sensorValue, 300, 1023, 0, NbrLEDs); // map to the number of LEDs  for (int led = 0; led < NbrLEDs; led++) { if (led < ledLevel ) { digitalWrite(ledPins[led], HIGH); // turn on pins less than the level  }  else { digitalWrite(ledPins[led],LOW); // turn off pins higher than // the level  }  }  }