const int trig = 2; const int echo = 3; const int LED1 = 5; const int LED2 = 6; const int LED3 = 7; const int LED4 = 8; int duration = 0; int distance = 0; void setup() { pinMode(trig , OUTPUT); pinMode(echo , INPUT); pinMode(LED1 , OUTPUT); pinMode(LED2 , OUTPUT); pinMode(LED3 , OUTPUT); pinMode(LED4 , OUTPUT); Serial.begin(9600); } void loop() { digitalWrite(trig , HIGH); delayMicroseconds(1000); digitalWrite(trig , LOW); duration = pulseIn(echo , HIGH); distance = (duration/2) / 28.5 ; Serial.println(distance); if ( distance <= 7 ) { digitalWrite(LED1, HIGH); } else { digitalWrite(LED1, LOW); } if ( distance <= 14 ) { digitalWrite(LED2, HIGH); } else { digitalWrite(LED2, LOW); } if ( distance <= 21 ) { digitalWrite(LED3, HIGH); } else { digitalWrite(LED3, LOW); } if ( distance <= 28 ) { digitalWrite(LED4, HIGH); } else { digitalWrite(LED4, LOW); } }