How to Use Single Brushed DC Motor Driver Carrier: Examples, Pinouts, and Specs

The Pololu DRV8838 Single Brushed DC Motor Driver Carrier is a compact and efficient module designed to control the speed and direction of a single brushed DC motor. It is based on the Texas Instruments DRV8838 motor driver IC and is ideal for applications requiring precise motor control with minimal space requirements. The module supports control via PWM signals, making it easy to interface with microcontrollers such as Arduino, Raspberry Pi, or other embedded systems.

• Robotics and automation
• Small motorized vehicles
• Conveyor belts and actuators
• DIY electronics projects
• Educational kits for motor control

The following table outlines the key technical details of the Pololu DRV8838 motor driver carrier:

The DRV8838 motor driver carrier has six pins. The table below describes each pin:

1. Power Supply: Connect the motor power supply to the VIN pin and ground to the GND pin. Ensure the voltage is within the specified range (0 V to 11 V).
2. Logic Power: Connect the microcontroller's logic voltage (1.8 V to 7 V) to the VCC pin.
3. Motor Connections: Attach the two terminals of the brushed DC motor to the OUT1 and OUT2 pins.
4. Control Pins: Use the IN1 and IN2 pins to control the motor's speed and direction:
   • Apply a PWM signal to IN1 for speed control.
   • Use IN2 to set the motor's direction (HIGH or LOW).

Below is an example of how to control the DRV8838 with an Arduino UNO:

// Define motor control pins
const int IN1 = 9; // PWM pin for speed control
const int IN2 = 8; // Direction control pin

void setup() {
  // Set motor control pins as outputs
  pinMode(IN1, OUTPUT);
  pinMode(IN2, OUTPUT);
}

void loop() {
  // Rotate motor forward at 50% speed
  analogWrite(IN1, 128); // PWM value (0-255) for speed
  digitalWrite(IN2, LOW); // Set direction to forward
  delay(2000); // Run for 2 seconds

  // Rotate motor backward at 75% speed
  analogWrite(IN1, 192); // PWM value (0-255) for speed
  digitalWrite(IN2, HIGH); // Set direction to backward
  delay(2000); // Run for 2 seconds

  // Stop the motor
  analogWrite(IN1, 0); // Set speed to 0
  delay(1000); // Wait for 1 second
}

• Ensure the motor's current requirements do not exceed the driver's maximum continuous current rating (1.7 A).
• Use a decoupling capacitor across the motor power supply (VIN and GND) to reduce noise and voltage spikes.
• Avoid reversing the polarity of the power supply connections, as this may damage the module.
• For optimal performance, ensure proper heat dissipation, especially when operating near the maximum current rating.

1. Motor Does Not Spin

   • Verify that the power supply is connected and providing the correct voltage.
   • Check the connections to the motor and ensure they are secure.
   • Confirm that the control signals (IN1 and IN2) are being sent correctly from the microcontroller.

2. Motor Spins in the Wrong Direction

   • Swap the connections to the motor terminals (OUT1 and OUT2).
   • Alternatively, reverse the logic level on the IN2 pin.

3. Driver Overheats

   • Ensure the motor's current draw does not exceed 1.7 A continuously.
   • Add a heatsink or improve ventilation around the driver.

4. PWM Control Not Working

   • Verify that the PWM signal is being generated correctly by the microcontroller.
   • Ensure the PWM frequency is within the recommended range (typically 20 kHz or higher).

Q: Can I use this driver with a 12 V motor?
A: No, the maximum motor voltage supported by the DRV8838 is 11 V. Using a 12 V motor may damage the driver.

Q: What happens if the motor stalls?
A: The DRV8838 includes overcurrent protection, which will disable the outputs if the current exceeds the limit. Reduce the load on the motor to prevent stalling.

Q: Can I control the motor without PWM?
A: Yes, you can set IN1 to HIGH or LOW for full-speed operation and use IN2 to control the direction.

Q: Is this driver compatible with 3.3 V logic?
A: Yes, the DRV8838 supports logic voltages as low as 1.8 V, making it compatible with 3.3 V systems.

By following this documentation, you can effectively integrate the Pololu DRV8838 Single Brushed DC Motor Driver Carrier into your projects for reliable and precise motor control.