How to Use DRV8825 : Examples, Pinouts, and Specs

The DRV8825 is a 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 smoother and more accurate motor movements. It features adjustable current control, over-temperature protection, and a wide operating voltage range, making it a versatile choice for robotics, 3D printers, CNC machines, and other automation systems.

• Robotics and automation systems
• 3D printers and 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
• Over-Temperature Protection: Yes
• Over-Current Protection: Yes
• Adjustable Current Control: Yes (via potentiometer)
• 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 Connections:

   • Connect the motor power supply to the VMOT and GND pins. Use a capacitor (e.g., 100µF) across these pins to reduce voltage spikes.
   • Connect the logic power supply (3.3V or 5V) to the VDD and GND pins.

2. Motor Connections:

   • Connect the two coils of the stepper motor to the OUT1A, OUT1B, OUT2A, and OUT2B pins. Ensure the correct pairing of motor wires.

3. Control Signals:

   • Connect the STEP and DIR pins to your microcontroller (e.g., Arduino UNO). Use digital pins to send step pulses and direction signals.
   • Optionally, connect the ENABLE pin to control driver activation.

4. Microstepping Configuration:

   • Set the MS1, MS2, and MS3 pins to the desired logic levels for the required microstepping mode.

5. Adjusting Current Limit:

   • Use the onboard potentiometer to set the current limit. Measure the voltage on the "REF" pin and calculate the current limit using the formula:

     Current Limit = VREF × 2
     

     (For example, if VREF = 0.5V, the current limit is 1A.)

6. Optional Connections:

   • Connect the RESET and SLEEP pins to logic HIGH to enable normal operation.
   • Monitor the FAULT pin for error conditions.

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

// Define pin connections
#define STEP_PIN 3  // Pin connected to STEP
#define DIR_PIN 4   // Pin connected to DIR

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 = clockwise)
}

void loop() {
  // Generate step pulses
  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 power supply voltage is within the specified range (8.2V to 45V).
• Use a heatsink or cooling fan if operating at high currents to prevent overheating.
• Avoid connecting or disconnecting the motor while the driver is powered to prevent damage.
• Always set the current limit to match your motor's rated current to avoid overloading.

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. Driver Overheating:

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

3. Erratic Motor Movement:

   • Cause: Noise on control signals or incorrect microstepping configuration.
   • Solution: Use pull-down resistors on control pins and verify MS1, MS2, and MS3 settings.

4. FAULT Pin Active (Low):

   • Cause: Over-temperature or over-current condition.
   • Solution: Reduce the current limit and ensure proper cooling.

5. Motor Vibrates but Does Not Rotate:

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

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

• Q: What is the maximum step pulse frequency?
  A: The DRV8825 can handle step pulse frequencies up to 250kHz.

• Q: Can I use the DRV8825 with a 12V power supply?
  A: Yes, the DRV8825 supports power supply voltages from 8.2V to 45V.

• Q: How do I calculate the current limit for my motor?
  A: Measure the VREF voltage and use the formula:
  Current Limit = VREF × 2.

By following this documentation, you can effectively use the DRV8825 stepper motor driver in your projects!