Noisy data using 3 MB1003 sensors in sequential operation mode

Using Arduino Sensors
1

Hi All,

I have connected 3 MB1003 ultrasonic sensors which are placed 60 cm apart from each other on the ceiling. The sensors are placed at an angle of 90 degree facing the floor.
The connections are made as per the datasheet

1965×650 307 KB

Here is my code

const int anPin1 = 0;
const int anPin2 = 1;
const int anPin3 = 2;
int triggerPin1 = 2;
long distance1, distance2, distance3;
long mm1, mm2, mm3;
long cm1, cm2, cm3;
void setup() {
Serial.begin(9600); // sets the serial port to 9600
pinMode(triggerPin1, OUTPUT);
}
void start_sensor(){
digitalWrite(triggerPin1,HIGH);
delay(96);
digitalWrite(triggerPin1,LOW);
}
void read_sensors(){
distance1 = analogRead(anPin1);
mm1=distance15;
cm1=mm1/10;
distance2 = analogRead(anPin2);
mm2=distance25;
cm2=mm2/10;
distance3 = analogRead(anPin3);
mm3=distance3*5;
cm3=mm3/10;
}
void print_all(){
Serial.print(cm1);Serial.print(",");
Serial.print(cm2);Serial.print(",");
Serial.print(cm3);Serial.print(",");
Serial.println();
}
void loop() {
start_sensor();
read_sensors();
print_all();
delay(100);
}

Can anyone suggest me on whats wrong that I am doing?

Noisy.PNG

2

Let me guess: the trigger pin triggers all sensors. The make a sound, all three at the same time and then they're listening for the echo. Guess what they will hear. Take two friends and go to a nearby tunnel. Then cry out load all three at the same time. Then try to distinguish which echo was from which side of the tunnel and from which person. That's about the job you expect from the ultrasonic sensors.