Iduino ST1099 User guide

Dual Ultrasonic Sensor Module(ST1099/ME140)

Pin Name

Description

“Vcc”

Power (5V DC)

“Trig”

Trigger the transmit signal

“Echo”

Echo the received echo signal

“Gnd”

Gnd

1.Instructions

The HC-SR04 is an inexpensive ultrasonic sensor that can sense not only if an object presents
itself, like a PIR sensor, but can also sense and relay the distance to that object.
Features:

 Power Supply :+5V DC
 Quiescent Current : <2mA
 Working Currnt: 15mA
 Effectual Angle: <15°
 Ranging Distance : 2cm – 400 cm/1" - 13ft
 Resolution : 0.3 cm
 Measuring Angle: 30 degree
 Trigger Input Pulse width: 10uS

2. Pin Instruction

3. Example
This example allows you display the defect distance on your ARDUIN’s Serial window.
Pin connection:
Vcc========== Power(5V DC)
Trig========== 12
Echo========== 13
Gnd===========Gnd

Picture connection as below:

Example code:

*********Code begin*********

#define trigPin 13
#define echoPin 12
#define led 11
#define led2 10

void setup() {
Serial.begin (9600);
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);
pinMode(led, OUTPUT);
pinMode(led2, OUTPUT);
}

void loop() {
long duration, distance;
digitalWrite(trigPin, LOW); // Added this line
delayMicroseconds(2); // Added this line
digitalWrite(trigPin, HIGH);
// delayMicroseconds(1000); - Removed this line
delayMicroseconds(10); // Added this line
digitalWrite(trigPin, LOW);
duration = pulseIn(echoPin, HIGH);
distance = (duration/2) / 29.1;
if (distance < 4) { // This is where the LED On/Off happens
digitalWrite(led,HIGH); // When the Red condition is met, the Green
LED should turn off