How can I stop my else if statement from running straight after my first if

Using Arduino Programming Questions
1

Hi,

I have added all my code below... Basically I am trying to get an ultrasonic sensor to know if there is an objet in front of it, the problem is that when i put my hand infront of the sensor, it sees thats the first object and thats fine but then instantly sees that as the second object also.

Do you know of a way i can leave the if statement or give the arduino a wait time before it can run the main loop again?

int distance_thresh = 12;
int object_count = 0;

#define trigPin 8
#define echoPin 9

void setup() {

pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);

Serial.begin(9600);

}

void loop() {
// Below is the calculation for the ultrasonic sensor to test how far away an object is
long duration, distance;
digitalWrite(trigPin, HIGH);
delayMicroseconds(1000);
digitalWrite(trigPin, LOW);
duration = pulseIn(echoPin, HIGH);
distance = (duration/2) / 29.1;
if (object_count == 0 && distance < distance_thresh){
Serial.println("First Object Found");
Serial.write("\n");
object_count = object_count + 1;
}
else if (object_count == 1 && distance < distance_thresh){
Serial.println("Second Object Found");
Serial.write("\n");
object_count = object_count + 1;
}
}

2

Welcome to the Forum. This is the second time you have posted code without using code tags. The code tags make the code look

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3 
distance = (duration/2) / 29.1;
    if (object_count == 0 && distance < distance_thresh){
          Serial.println("First Object Found");
          Serial.write("\n");
          object_count = object_count + 1;
  }
    else if (object_count == 1 && distance < distance_thresh){ 
          Serial.println("Second Object Found");
          Serial.write("\n");
          object_count = object_count + 1;
    }

You measure the distance to an object. If the distance is small enough, you count the object.

Then, loop() runs again. The object distance, a few milliseconds later, is still the same, so the if part is false, and the else if part is true, so you do that.

Then, loop() runs again. The object distance, a few milliseconds later, is still the same, so the if part is false, and the else if part is false, so you do the else part (or would if there were one).

You need to explain why you think this has a ghost of a chance of doing something useful.