Need Help My Code Is Not Working As It intended

Programming
1 
int in1 = 2;
int in2 =3;
int pir_sensor = 8;
void setup() {
  // put your setup code here, to run once:
  pinMode(pir_sensor, INPUT);
  pinMode(in1, OUTPUT);
  pinMode(in2, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
  int value = digitalRead(pir_sensor);
  if (value == HIGH){
    Serial.println(value);
    digitalWrite(in1, HIGH);
    digitalWrite(in2, LOW);
    delay(2000);
    digitalWrite(in1, LOW);
    digitalWrite(in2, HIGH);
    delay(2000);
  }
  else{
    Serial.println(value);
  }
}

In the above code in1 and in2 are the inputs of motor drive when i place my hand near PIR Sensor its value become 1 and if statement start but it is looping over if system and its value remains 1 for quite some time even removing my hand. Also polarity of motor is not changing…

2

Hello, ¿Can you post some pictures of the hardware setup (micro, PIR, motors, connections)? ¿What PIR sensor are you using?

3

The problem is with variable value. Its never changes its state once the if statement is true. Make the following changes.

  bool value = digitalRead(pir_sensor);

  if (value == HIGH){
    value = LOW;
    Serial.println(value);
    digitalWrite(in1, HIGH);
    digitalWrite(in2, LOW);
    delay(2000);
    digitalWrite(in1, LOW);
    digitalWrite(in2, HIGH);
    delay(2000);
  }
4

If you r coding in arduino ide no need of value = low

Because the program will run line by line
When it come out of if statement it will again read the line" bool value = digitalRead(pir_sensor)" it will make the changes

I hop you get my point

The main problem in the code was the was you difine the variable
In before code they difine as “int”
*Int" can store -32,768 to 32,767 as it’s value

In if statement you r using bool value
Bool can only store 1 or 0 in it. means (HIGH OR LOW) value in it

I hope you understand what i mean

5

But definitions of HIGH and LOW macros in Arduino.h are:

#define HIGH 0x1
#define LOW 0x0

And in C++ standard: “if either operand is unsigned, the other shall be converted to unsigned.”, then comparison “if (value == HIGH)” should not be a problem.

On the other hand, I suggest to move the declaration of variable ‘value’ in the setup section and to do assignments to ‘value’ in the loop . In order to avoid redefinitions of ‘value’ variable.
Maybe function delay is not the best way to generate PWM signals to control motors. Furtheremore If you are using an H-Bridge to control motor you need a “dead time” between the polarity change.

6

As per knowledge you use true or false with bool, high and low works well with int as you can even use 1 for high and 0 for low. So the problem was the value of pir sensor was high after the if statement was true and it was never set to low again.