#define ECHO_PIN1 15 //Pins for Sensor 1
#define TRIG_PIN1 2 //Pins for Sensor 1
#define ECHO_PIN2 5 //Pins for Sensor 2
#define TRIG_PIN2 18 //Pins for Sensor 2
#define ECHO_PIN3 26 //Pins for Sensor 3
#define TRIG_PIN3 27 //Pins for Sensor 3
int LEDPIN1 = 13; 
int LEDPIN2 = 12; 
int LEDPIN3 = 14; 
void setup() { 
Serial.begin(115200); 
pinMode(LEDPIN1, OUTPUT); 
pinMode(TRIG_PIN1, OUTPUT); 
pinMode(ECHO_PIN1, INPUT); 
pinMode(LEDPIN2, OUTPUT); 
pinMode(TRIG_PIN2, OUTPUT); 
pinMode(ECHO_PIN2, INPUT); 
pinMode(LEDPIN3, OUTPUT); 
pinMode(TRIG_PIN3, OUTPUT); 
pinMode(ECHO_PIN3, INPUT); 
} 
float readDistance1CM() { 
digitalWrite(TRIG_PIN1, LOW); 
delayMicroseconds(2); 
digitalWrite(TRIG_PIN1, HIGH); 
delayMicroseconds(10);
digitalWrite(TRIG_PIN1, LOW); 
int duration = pulseIn(ECHO_PIN1, HIGH); 
return duration * 0.034 /2 ; 
} 
float readDistance2CM() { 
digitalWrite(TRIG_PIN2, LOW); 
delayMicroseconds(2); 
digitalWrite(TRIG_PIN2, HIGH); 
delayMicroseconds(10); 
digitalWrite(TRIG_PIN2, LOW); 
int duration = pulseIn(ECHO_PIN2, HIGH); 
return duration * 0.034 / 2; 
} 
float readDistance3CM() { 
digitalWrite(TRIG_PIN3, LOW); 
delayMicroseconds(2); 
digitalWrite(TRIG_PIN3, HIGH); 
delayMicroseconds(10); 
digitalWrite(TRIG_PIN3, LOW); 
int duration = pulseIn(ECHO_PIN3, HIGH); 
return duration * 0.034 / 2; 
} 
void loop() { 
 float distance1 = readDistance1CM(); 
 float distance2 = readDistance2CM(); 
 float distance3 = readDistance3CM(); 
 bool isNearby1 = distance1 > 200; 
 digitalWrite(LEDPIN1, isNearby1); 
 
 bool isNearby2 = distance2 > 200; 
 digitalWrite(LEDPIN2, isNearby2); 
 
 bool isNearby3 = distance3 > 200; 
 digitalWrite(LEDPIN3, isNearby3); 
 Serial.print("Measured distance: "); 
 Serial.println(readDistance1CM()); 
 Serial.println(readDistance2CM()); 
 Serial.println(readDistance3CM()); 
 delay(100); 
}