How to Use DRV8825 : Examples, Pinouts, and Specs

The DRV8825 is a high-performance stepper motor driver designed to control bipolar stepper motors with precision and efficiency. Manufactured by Arduino, this component (Part ID: Stepper motor driver) supports microstepping, allowing for smooth and accurate motor operation. It features adjustable current control, over-temperature protection, and a wide operating voltage range, making it ideal for applications in robotics, 3D printing, CNC machines, and other automation systems.

• Robotics and automation systems
• 3D printers
• CNC machines
• Camera sliders and gimbals
• Precision positioning systems

• Operating Voltage Range: 8.2V to 45V
• Maximum Output Current: 2.2A per coil (with sufficient cooling)
• Microstepping Modes: Full-step, 1/2, 1/4, 1/8, 1/16, and 1/32 steps
• Logic Voltage: 3.3V or 5V compatible
• Current Control: Adjustable via potentiometer
• Protection Features: Over-temperature, over-current, and under-voltage lockout
• Dimensions: 15mm x 20mm (approx.)

The DRV8825 module has 16 pins. Below is the pinout and description:

The microstepping mode is configured using the MS1, MS2, and MS3 pins as shown below:

1. Power Supply:

   • Connect VMOT and GND to the motor power supply (8.2V to 45V).
   • Add a capacitor (100µF or higher) across VMOT and GND to prevent voltage spikes.
   • Connect VDD and GND to the logic power supply (3.3V or 5V).

2. Motor Connections:

   • Connect the stepper motor coils to the 1A, 1B, 2A, and 2B pins. Ensure the correct pairing of motor wires.

3. Control Signals:

   • Connect STEP and DIR pins to the microcontroller's digital output pins.
   • Use MS1, MS2, and MS3 to set the desired microstepping mode.
   • Optionally, connect ENABLE, RESET, and SLEEP pins for additional control.

4. Adjusting Current Limit:

   • Use the onboard potentiometer to set the current limit. This prevents overheating and ensures safe operation.
   • Formula for current limit:
     Current Limit = VREF × 2
     (where VREF is the voltage measured at the potentiometer).

Below is an example code to control a stepper motor using the DRV8825 and an Arduino UNO:

// Define pin connections
#define STEP_PIN 3  // Connect to STEP pin on DRV8825
#define DIR_PIN 4   // Connect to DIR pin on DRV8825

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

  digitalWrite(DIR_PIN, HIGH); // Set initial direction (HIGH or LOW)
}

void loop() {
  // Generate step pulses
  digitalWrite(STEP_PIN, HIGH); // Step pulse HIGH
  delayMicroseconds(500);       // Wait 500 microseconds
  digitalWrite(STEP_PIN, LOW);  // Step pulse LOW
  delayMicroseconds(500);       // Wait 500 microseconds
}

• Always power off the system before connecting or disconnecting the motor.
• Use a heat sink or cooling fan if operating at high currents.
• Avoid exceeding the voltage and current ratings to prevent damage.
• Ensure proper grounding to avoid noise and instability.

1. Motor Not Moving:

   • Cause: Incorrect wiring or insufficient power supply.
   • Solution: Double-check motor connections and ensure the power supply meets voltage and current requirements.

2. Overheating Driver:

   • Cause: Current limit set too high or inadequate cooling.
   • Solution: Adjust the current limit using the potentiometer and add a heat sink or fan.

3. Erratic Motor Movement:

   • Cause: Noise or incorrect microstepping configuration.
   • Solution: Use decoupling capacitors and verify MS1, MS2, and MS3 settings.

4. FAULT Pin Active:

   • Cause: Over-temperature or over-current condition.
   • Solution: Allow the driver to cool down and reduce the current limit.

5. Motor Vibrates but Does Not Rotate:

   • Cause: Incorrect stepper motor wiring.
   • Solution: Verify the correct pairing of motor wires.

• Q: Can the DRV8825 drive unipolar stepper motors?
  A: No, the DRV8825 is designed for bipolar stepper motors only.

• Q: What is the maximum microstepping resolution?
  A: The DRV8825 supports up to 1/32 microstepping.

• Q: Can I use the DRV8825 with a 12V power supply?
  A: Yes, the DRV8825 operates within a voltage range of 8.2V to 45V.

• Q: How do I reset the driver?
  A: Pull the RESET pin low momentarily to reset the driver.

By following this documentation, users can effectively integrate the DRV8825 into their projects and troubleshoot common issues with ease.