int trigPin = 2; // Sensor Trip pin connected to Arduino pin D3 int echoPin = 3; // Sensor Echo pin connected to Arduino pin D2 int dataOut = 13; // RF Module connects here long duration, Distance; void setup() { Serial.begin(115200); pinMode(trigPin, OUTPUT); pinMode(echoPin, INPUT); pinMode(dataOut, OUTPUT); } void loop() { digitalWrite(trigPin, LOW); delayMicroseconds(2); digitalWrite(trigPin, HIGH); delayMicroseconds(10); digitalWrite(trigPin, LOW); duration = pulseIn(echoPin, HIGH); Distance = (duration/2) / 74; // Distance in Inches if(Distance < 10){ // When an object is at a close proximity of 20 Inches digitalWrite(dataOut, LOW); delay(200); } else{ digitalWrite(dataOut, HIGH); delay(200); } Serial.println(Distance); }