ir reading no much diference ....

I hope someone can help me with this
I have two ir (transmiter-receiver) and I need to know when it is someting that interrupts the signal. I mean someting is between them …
the hardware I have is this one

FROM THE SAME PAGE

This is a very simple set up: The IRL 80 A IR sender (glowing blue at bottom right) has its long lead connected to arduino 5, the short lead to ground. Behind it is the LPT 80 A IR receiver (hard to see because clear) with its long lead connected to 5V and short lead connected to both A1 on Arduino and to a 10 K resistor that goes to ground.


I need very small sensors that is why I chose those for this.

If nothing is between the sensors I got from 1013 to 1017 in the A0 port (analog reading)
if the sensors are covered I got from 1016 to 1020 …

The problem is I got 1016 and 1017 in both cases. I expected to get diferent numbers so I can see a diference to know if the sensors are covered or not.

The method I have to get those values is the next one.
Any help will be very good for me since I do not know much about this.

int getSensorsValues( char vl_To_Return ) {
  int minValue ; int maxValue ; unsigned long time ; int irRead ;
  unsigned long st ; unsigned long sample ;
  
  minValue = 32767 ;
  maxValue = -32768 ;
  
  sample = (millis() + 100) ;
  time = (millis() + 10000) ;
  st = (millis() + 2000) ;
  
  //digitalWrite( _Receptor_PWM, HIGH ) ;  
  //digitalWrite( _Trasmisor_PWM, HIGH ) ;
  
  do {

    irRead = analogRead( _Receptor_ANLG ) ;
    
     //Serial.println( irRead ) ;
  
    if ( millis() > sample ) {
      if ( irRead < minValue ) {
        minValue = irRead ;
      }
      if ( irRead > maxValue ) {
        maxValue = irRead ;
      }
    }
    
    if ( millis() >= (st + 2000) ) {
      lcd.clear() ;
      lcd.setCursor ( 0, 0 );        // columna fila
      lcd.print( "Mn: " ) ;
      lcd.print( minValue ) ;
      lcd.setCursor ( 0, 1 ) ;        // columna fila
      lcd.print( "Mx: " ) ;
      lcd.print( maxValue ) ;
      
      st = millis() ;
    }
    
  } while (millis() <= time) ;

  //digitalWrite( _Receptor_PWM, LOW ) ;  
  //digitalWrite( _Trasmisor_PWM, LOW ) ;

  
  lcd.clear() ;
  lcd.setCursor ( 0, 0 );        // columna fila
  lcd.print( "Mn: " ) ;
  lcd.print( minValue ) ;
  lcd.setCursor ( 0, 1 ) ;        // columna fila
  lcd.print( "Mx: " ) ;
  lcd.print( maxValue ) ;

  
  if ( vl_To_Return == 'X' ) {   // Mayor valor
    return maxValue ;
  } else if ( vl_To_Return == 'N' ) {    // Menor valor
    return minValue ;
  }  
  
}

I hope you have just forgot to tell us about the resistor in series with the IR led. There are some other problems, too, such as the fact that the LPT phototransistor is clear, and as such it will react to daylight as well. The reason you read such high A0 values could be because the phototransistor is saturated with daylight. You might have better results reducing the 10k resistor to say, 1k.