help needed safety device for escalator

Other Hardware Sensors
1

I am trying to make an alarm device that Alarm when some one try to enter (going up escalator) to avoid an accident.
Idea is that install 2 sensors and one led Idea is that if S1 trigger 1st and then S2 LED will be lights up.
and vice versa do nothing.

int ledPin1 = 3;
int sensor1 =0;
int sensor2 =0;

int trigPin1 = 6;
int echoPin1 = 7;

int trigPin2 = 8;
int echoPin2 = 9;
void setup() {
  Serial.begin (9600);
  pinMode(trigPin1, OUTPUT);
  pinMode(echoPin1, INPUT);
 
  pinMode(trigPin2, OUTPUT);
  pinMode(echoPin2, INPUT);
 
  pinMode(ledPin1, OUTPUT);
 
}

void loop() {
Serial.println("\n");
  int duration1, distance1;
  digitalWrite (trigPin1, HIGH);
  delayMicroseconds (10);
  digitalWrite (trigPin1, LOW);
  duration1 = pulseIn (echoPin1, HIGH);
  distance1 = (duration1/2) / 29.1;

      Serial.print("1st Sensor: ");
      Serial.print(distance1); 
      Serial.print("cm  ");

 if (distance1 <= 80){  // Change the number for long or short distances.
      sensor1 =1;
     } else {
   sensor1 =0;
    }
Serial.print(sensor1   );
    int duration2, distance2;
    digitalWrite (trigPin2, HIGH);
    delayMicroseconds (10);
    digitalWrite (trigPin2, LOW);
    duration2 = pulseIn (echoPin2, HIGH);
    distance2 = (duration2/2) / 29.1;
    Serial.print("   2nd Sensor: ");
    Serial.print(distance2); 
    Serial.print("cm  ");
    if (distance2 <= 80 ) {  // Change the number for long or short distances.
    sensor2 =1;
    
    }else {
     sensor2 =0;
    }  
   Serial.print(sensor2);   
     
// wrong way Control logic
if (sensor1 == (1) && sensor2 == (1)) {
    digitalWrite (ledPin1, HIGH);
    }
 else {
      digitalWrite (ledPin1, LOW);
   
    } 
   

if (sensor1 == (0) && sensor2  == (0)) {
  //digitalWrite (ledPin1, LOW);
  //sensor2 = 0;
    }
 else {
     // digitalWrite (ledPin1, LOW);
 }
}

layout.jpg
layout.jpg815×597 53.8 KB

2

You can’t make safety related equipment with Arduino .

3

Of course you can - whether it's a good idea depends mostly on the skills of the person building it, and the actual application. Living in a city rife with escalators I've never seen any accidents or near accidents or so with people taking the wrong way, so no seriously risks anyway. The apparent use of cheap ultrasound sensors is more of an issue here I'd say.

The reliable detection of walking direction, especially when people pass by in groups, is very hard.

School project?