====== Controlling a DC Motor ======

This scenario demonstrates how to control a DC motor's rotation direction and speed using Arduino with the Pololu TB6612FNG Dual Motor Driver.

===== Prerequisites =====
  * Familiarize yourself with Arduino hardware reference.
  * Understand basic PWM concepts.
  * Familiarity with the Pololu TB6612FNG motor driver.

===== Hardware Connections =====
| Motor Driver Pin | Arduino Pin |
|------------------|-------------|
| AIN1             | 12          |
| AIN2             | 11          |
| PWMA             | 3 (PWM)     |

**Motor specifications:**
  * Voltage: 12 V DC
  * Speed: 5 rpm
  * Torque: 20 N·cm
  * Shaft Diameter: 4 mm

===== Suggested Knowledge Resources =====
  * Arduino programming fundamentals
  * [[taltech:arduino:hardware|Arduino Uno Hardware Reference]]

===== Task =====
Implement a program that rotates the DC motor forward at full speed for 5 seconds, pauses for 2 seconds, reverses at half speed for 5 seconds, then pauses again for 2 seconds, repeatedly.

===== Steps =====

=== Step 1: Define Pins ===
<code c>
const int AIN1 = 12;
const int AIN2 = 11;
const int PWMA = 3;
</code>

=== Step 2: Setup ===
Configure pin modes:
<code c>
void setup() {
  pinMode(AIN1, OUTPUT);
  pinMode(AIN2, OUTPUT);
  pinMode(PWMA, OUTPUT);
}
</code>

=== Step 3: Control Loop ===
Implement motor control logic:
<code c>
void loop() {
  // Rotate Forward at full speed
  digitalWrite(AIN1, HIGH);
  digitalWrite(AIN2, LOW);
  analogWrite(PWMA, 255);  // Full speed
  delay(5000);             // 5 seconds

  // Stop motor
  digitalWrite(AIN1, LOW);
  digitalWrite(AIN2, LOW);
  delay(2000);             // 2 seconds pause

  // Rotate Reverse at half speed
  digitalWrite(AIN1, LOW);
  digitalWrite(AIN2, HIGH);
  analogWrite(PWMA, 128);  // Half speed
  delay(5000);             // 5 seconds

  // Stop motor again
  digitalWrite(AIN1, LOW);
  digitalWrite(AIN2, LOW);
  delay(2000);             // 2 seconds pause
}
</code>

===== Validation =====
Observe the motor rotating in both directions with clear speed differences. Verify pauses between rotations.

===== Troubleshooting =====
If the motor doesn’t rotate or behaves erratically:
  * Check power supply (motor needs 12V DC).
  * Confirm motor driver connections.
  * Verify Arduino pin assignments match the code.