How to Use DRV8834: Examples, Pinouts, and Specs

The DRV8834 Low-Voltage Stepper Motor Driver Carrier by Pololu is a compact and versatile motor driver designed to control bipolar stepper motors. It features dual H-bridge outputs, adjustable current control, and microstepping capabilities, allowing for precise and efficient motor control. The DRV8834 is particularly well-suited for low-voltage applications, operating with motor supply voltages as low as 2.5V. Additionally, it includes built-in protection features such as overcurrent protection, thermal shutdown, and undervoltage lockout, ensuring reliable operation in demanding environments.

• Robotics and automation systems
• 3D printers and CNC machines
• Camera gimbals and pan-tilt mechanisms
• Precision positioning systems
• Educational and DIY electronics projects

The following table outlines the key technical details of the DRV8834:

The DRV8834 has 16 pins, which are described in the table below:

1. Power Connections:

   • Connect the motor power supply (VMOT) to the VMOT pin and ground to the GND pin. Use a decoupling capacitor (e.g., 100 µF) close to the VMOT pin to reduce noise.
   • Connect the logic power supply (VCC) to the VCC pin and ground to the GND pin.

2. Motor Connections:

   • Connect the two coils of the stepper motor to the A1, A2, B1, and B2 pins. Ensure the correct pairing of the motor wires.

3. Control Inputs:

   • Use the STEP pin to send step pulses to the driver. Each rising edge advances the motor by one step.
   • Use the DIR pin to control the rotation direction of the motor.
   • Configure the microstepping mode by setting the M0 and M1 pins according to the desired mode (refer to the datasheet for the mode selection table).

4. Current Limiting:

   • Adjust the current limit using the onboard potentiometer. This prevents the motor from drawing excessive current and overheating.

5. Optional Features:

   • Use the SLEEP pin to put the driver into low-power mode when not in use.
   • Monitor the FAULT pin for error conditions such as overcurrent or thermal shutdown.

Below is an example of how to control a stepper motor using the DRV8834 and an Arduino UNO:

// Define pin connections
#define STEP_PIN 3  // Connect to the STEP pin of DRV8834
#define DIR_PIN 4   // Connect to the DIR pin of DRV8834

void setup() {
  pinMode(STEP_PIN, OUTPUT); // Set STEP pin as output
  pinMode(DIR_PIN, OUTPUT);  // Set DIR pin as output

  digitalWrite(DIR_PIN, LOW); // Set initial direction (LOW = clockwise)
}

void loop() {
  // Generate step pulses to move the motor
  digitalWrite(STEP_PIN, HIGH); // Set STEP pin HIGH
  delayMicroseconds(500);       // Wait 500 microseconds
  digitalWrite(STEP_PIN, LOW);  // Set STEP pin LOW
  delayMicroseconds(500);       // Wait 500 microseconds
}

• Ensure the motor supply voltage (VMOT) and logic voltage (VCC) are within the specified ranges.
• Avoid connecting or disconnecting the motor while the driver is powered to prevent damage.
• Use appropriate heat dissipation methods if operating near the maximum current rating.

1. Motor Not Moving:

   • Verify the STEP and DIR signals are being sent correctly.
   • Check the motor connections to ensure proper wiring.
   • Ensure the current limit is set appropriately for the motor.

2. Overheating:

   • Reduce the current limit using the potentiometer.
   • Improve heat dissipation by adding a heatsink or increasing airflow.

3. FAULT Pin Active (Low):

   • Check for overcurrent or thermal shutdown conditions.
   • Ensure the motor supply voltage is within the specified range.

4. Erratic Motor Movement:

   • Verify the microstepping mode settings (M0 and M1 pins).
   • Ensure the STEP signal timing meets the minimum pulse width requirements.

Q: Can the DRV8834 drive unipolar stepper motors?
A: No, the DRV8834 is designed for bipolar stepper motors only.

Q: What is the maximum step rate supported by the DRV8834?
A: The maximum step rate depends on the STEP signal timing. Refer to the datasheet for the minimum pulse width requirements.

Q: Can I use the DRV8834 with a 12V motor?
A: No, the maximum motor supply voltage for the DRV8834 is 10.8V. Using a higher voltage may damage the driver.

Q: How do I reset the driver after a fault condition?
A: Toggle the SLEEP pin or cycle the power to reset the driver. Ensure the fault condition is resolved before restarting.