How to Use Polulu DRV 8874: Examples, Pinouts, and Specs

The Pololu DRV8874 (Manufacturer Part ID: 4035) is a compact and versatile motor driver designed to control both DC motors and stepper motors. It features a high-efficiency H-bridge design, allowing it to handle up to 3A of continuous current per channel. This driver is equipped with adjustable current limiting, making it suitable for a wide range of motor control applications. Its robust design and built-in protection features make it ideal for hobbyists, engineers, and professionals working on robotics, automation, and other motor-driven projects.

• Robotics and automation systems
• Electric vehicles and drones
• Conveyor belts and industrial machinery
• DIY projects involving DC or stepper motors
• Prototyping motor control circuits

The following table outlines the key technical details of the Pololu DRV8874 motor driver:

The Pololu DRV8874 features a 12-pin interface. The table below describes each pin:

1. Power Connections:

   • Connect the motor power supply to the VIN pin and ground to the GND pin.
   • Connect the logic power supply (e.g., 5V from a microcontroller) to the VCC pin and its ground to the GND pin.

2. Motor Connections:

   • Connect the motor terminals to the OUT1 and OUT2 pins.

3. Control Signals:

   • Use the PWM pin to control the motor speed by providing a PWM signal.
   • Use the DIR pin to set the motor's direction (HIGH for one direction, LOW for the other).

4. Current Limiting:

   • Adjust the current limit by setting the VREF voltage. Refer to the datasheet for the formula to calculate the current limit.

5. Sleep Mode:

   • To reduce power consumption, pull the nSLEEP pin LOW to put the driver into sleep mode.

6. Fault Monitoring:

   • Monitor the nFAULT pin to detect issues such as overcurrent or overtemperature conditions.

Below is an example of how to control a DC motor using the Pololu DRV8874 and an Arduino UNO:

// Define pin connections
const int pwmPin = 9;    // PWM pin connected to DRV8874 PWM
const int dirPin = 8;    // Direction pin connected to DRV8874 DIR
const int sleepPin = 7;  // Sleep pin connected to DRV8874 nSLEEP

void setup() {
  // Set pin modes
  pinMode(pwmPin, OUTPUT);
  pinMode(dirPin, OUTPUT);
  pinMode(sleepPin, OUTPUT);

  // Wake up the motor driver
  digitalWrite(sleepPin, HIGH); // Set nSLEEP HIGH to enable the driver
}

void loop() {
  // Set motor direction
  digitalWrite(dirPin, HIGH); // HIGH for forward, LOW for reverse

  // Set motor speed
  analogWrite(pwmPin, 128); // 50% duty cycle (range: 0-255)

  delay(2000); // Run motor for 2 seconds

  // Stop the motor
  analogWrite(pwmPin, 0); // Set PWM to 0 to stop the motor

  delay(2000); // Wait for 2 seconds
}

• Ensure the motor power supply voltage is within the specified range (4.5V to 37V).
• Avoid exceeding the continuous current rating of 3A to prevent damage.
• Use proper heat dissipation methods if operating near the maximum current limit.
• Double-check all connections before powering the circuit to avoid short circuits.

1. Motor Not Spinning:

   • Verify that the nSLEEP pin is set HIGH to enable the driver.
   • Check the PWM signal and ensure it is not set to 0.
   • Confirm that the motor power supply is connected and within the specified voltage range.

2. Driver Overheating:

   • Ensure the current limit is set appropriately using the VREF pin.
   • Add a heatsink or improve ventilation if operating at high currents.

3. nFAULT Pin is LOW:

   • This indicates a fault condition. Check for overcurrent, overtemperature, or undervoltage issues.
   • Reduce the load on the motor or adjust the current limit.

4. Motor Spins in the Wrong Direction:

   • Reverse the logic level on the DIR pin or swap the motor connections on OUT1 and OUT2.

Q: Can the DRV8874 drive stepper motors?
A: Yes, the DRV8874 can drive stepper motors in full-step or microstepping modes. Use the MODE pin to configure the driver for stepper motor control.

Q: What happens if the current exceeds the limit?
A: The driver will enter current limiting mode to protect itself and the motor. Prolonged overcurrent conditions may trigger a fault.

Q: Is the DRV8874 compatible with 3.3V logic?
A: Yes, the driver supports logic levels from 1.8V to 5.5V, making it compatible with 3.3V and 5V systems.

Q: Can I use the DRV8874 with a battery-powered system?
A: Yes, as long as the battery voltage is within the operating range (4.5V to 37V).