user20381: I am controlling 2 motors from my Arduino Pro Mini and L293D motor driver module. Problem is, I have to set a pin high and after 1 second set it to LOW. But that doesn't happen... The pin just stays HIGH and is never LOW. 
Here's my Code - 
    int IN2Left = 10;
    int E1 = 12;
    int E2 = 7;
    int IN3RevRight = 6;
    int trigPin1 = A0;
    int echoPin1 = A1;
    int distance1 = 0;
    int IN4Right = 5;
    int IN1RevLeft = 11;

    void setup()
    {
      pinMode(IN2Left, OUTPUT);
      pinMode(E1, OUTPUT);
      pinMode(E2, OUTPUT);
      pinMode(IN3RevRight, OUTPUT);
      pinMode(IN4Right, OUTPUT);
      pinMode(IN1RevLeft, OUTPUT);
      pinMode(trigPin1, OUTPUT);
      pinMode(echoPin1, INPUT);
      pinMode(13, OUTPUT);
      Serial.begin(9600);
    }

    void loop() {
  digitalWrite(13, HIGH);
  digitalWrite(E1, HIGH);
  digitalWrite(E2, HIGH);
  digitalWrite(IN2Left, HIGH);
  digitalWrite(IN4Right, HIGH);
  delay(3000);
  digitalWrite(IN4Right, LOW);
  digitalWrite(IN3RevRight,HIGH);
  delay(500);
  digitalWrite(IN3RevRight, LOW);
  digitalWrite(IN4Right, HIGH);
  delay(1500);
  digitalWrite(IN2Left, LOW);
  digitalWrite(IN1RevLeft, HIGH);
  delay(500);
  digitalWrite(IN1RevLeft, LOW);
  digitalWrite(IN2Left, HIGH);
  delay(100000);
    }

The IN2Left Pin never goes LOW... I am assuming a faulty Arduino but my Arduino seems to be working just fine as it runs other stuff (tested blink and reading an Ultrasonic sensor) just fine.
My deadline is 2 hours from now...
EDIT: Here's the complete void loop function... Note the two pins on top which go HIGH? They Never go LOW again in the entire code.

user368: Your code sets it high, delays for 1000ms, sets it low, and then... turns around and sets it high almost immediately after. Try delaying in between.

user10794:   digitalWrite(IN2Left, HIGH);
  delay(1000);
  digitalWrite(IN2Left, LOW);

It would go LOW for a few microseconds. Maybe put a delay after going LOW?

20381: <p>I am controlling 2 motors from my Arduino Pro Mini and L293D motor driver module. Problem is, I have to set a pin high and after 1 second set it to LOW. But that doesn't happen... The pin just stays HIGH and is never LOW. </p>

<p>Here's my Code - </p>

<pre><code>    int IN2Left = 10;
    int E1 = 12;
    int E2 = 7;
    int IN3RevRight = 6;
    int trigPin1 = A0;
    int echoPin1 = A1;
    int distance1 = 0;
    int IN4Right = 5;
    int IN1RevLeft = 11;

    void setup()
    {
      pinMode(IN2Left, OUTPUT);
      pinMode(E1, OUTPUT);
      pinMode(E2, OUTPUT);
      pinMode(IN3RevRight, OUTPUT);
      pinMode(IN4Right, OUTPUT);
      pinMode(IN1RevLeft, OUTPUT);
      pinMode(trigPin1, OUTPUT);
      pinMode(echoPin1, INPUT);
      pinMode(13, OUTPUT);
      Serial.begin(9600);
    }

    void loop() {
  digitalWrite(13, HIGH);
  digitalWrite(E1, HIGH);
  digitalWrite(E2, HIGH);
  digitalWrite(IN2Left, HIGH);
  digitalWrite(IN4Right, HIGH);
  delay(3000);
  digitalWrite(IN4Right, LOW);
  digitalWrite(IN3RevRight,HIGH);
  delay(500);
  digitalWrite(IN3RevRight, LOW);
  digitalWrite(IN4Right, HIGH);
  delay(1500);
  digitalWrite(IN2Left, LOW);
  digitalWrite(IN1RevLeft, HIGH);
  delay(500);
  digitalWrite(IN1RevLeft, LOW);
  digitalWrite(IN2Left, HIGH);
  delay(100000);
    }
</code></pre>

<p>The <code>IN2Left</code> Pin never goes LOW... I am assuming a faulty Arduino but my Arduino seems to be working just fine as it runs other stuff (tested blink and reading an Ultrasonic sensor) just fine.</p>

<p>My deadline is 2 hours from now...</p>

<p>EDIT: Here's the complete void loop function... Note the two pins on top which go HIGH? They Never go LOW again in the entire code.</p>
 368: <p>Your code sets it high, delays for 1000ms, sets it low, and then... turns around and sets it high almost immediately after. Try delaying in between.</p>
 10794: <pre><code>  digitalWrite(IN2Left, HIGH);
  delay(1000);
  digitalWrite(IN2Left, LOW);
</code></pre>

<p>It would go LOW for a few microseconds. Maybe put a delay after going LOW?</p>
