How to Use SparkFun AutoDriver - Stepper Motor Driver (v10): Examples, Pinouts, and Specs

The SparkFun AutoDriver is a sophisticated stepper motor driver that offers a versatile solution for driving bipolar stepper motors in various applications. It is based on the STMicroelectronics L6470 chip, which provides advanced features such as adjustable current control, microstepping, and built-in overcurrent protection. This driver is suitable for projects requiring precise motor control, such as 3D printers, CNC machines, and robotics.

• 3D Printing
• CNC Machines
• Robotics
• Precision Positioning Systems
• Automated Equipment

• Motor Type: Bipolar Stepper
• Maximum Current per Phase: 1.5A
• Voltage Range: 8V to 45V
• Microstepping: Up to 1/128
• Communication: SPI for configuration and control, Step/Direction interface
• Built-in Features: Overcurrent protection, thermal shutdown, under-voltage lockout

1. Power Connections:

   • Connect the motor power supply to the VMOT and GND pins.
   • Connect the logic power supply to the VDD and GND pins.

2. Motor Connections:

   • Connect the bipolar stepper motor coils to the A1, A2, B1, and B2 pins.

3. Control Connections:

   • For step/direction control, connect the STEP and DIR pins to the controlling microcontroller.
   • For SPI communication, connect the SCK, SDI, SDO, and CSN pins to the corresponding SPI pins on the microcontroller.

4. Configuration:

   • Use the SPI interface to configure the AutoDriver settings such as current limit, step mode, and other parameters.

5. Operation:

   • Send step pulses to the STEP pin to move the motor. Change the logic level of the DIR pin to control the direction.

• Ensure that the power supply voltage and current ratings are within the specifications of the AutoDriver.
• Use a decoupling capacitor close to the VMOT and VDD pins to minimize voltage spikes.
• Configure the current limit to match the stepper motor's specifications to prevent damage.
• Avoid disconnecting the motor while the driver is powered to prevent damage to the driver.
• Use proper heat sinking if operating the driver at high currents for extended periods.

• Motor not moving: Check power supply connections, motor connections, and SPI configuration.
• Overheating: Ensure proper current settings and heat sinking.
• Noise or erratic movement: Adjust the current limit and check for proper microstepping configuration.

• Verify all connections and solder joints.
• Use the FLAG pin to diagnose fault conditions.
• Ensure that the SPI communication is correctly established with the microcontroller.
• Check the thermal and overcurrent protection settings.

• Q: Can I drive two motors simultaneously with one AutoDriver?

  • A: No, the AutoDriver is designed to control one bipolar stepper motor. You will need one driver per motor.

• Q: What is the maximum step frequency?

  • A: The maximum step frequency depends on the motor and power supply characteristics. Refer to the L6470 datasheet for detailed timing information.

• Q: How do I set the current limit?

  • A: The current limit is set via SPI commands. Refer to the L6470 datasheet and the SparkFun AutoDriver library for the correct commands.

#include <SPI.h>
#include <SparkFunAutoDriver.h>

// Define the chip select pin for the AutoDriver
#define CSPin 10

// Create an instance of the AutoDriver
AutoDriver motor(CSPin);

void setup() {
  // Start the SPI bus
  SPI.begin();
  
  // Reset the AutoDriver
  motor.resetSettings();
  
  // Set the motor current limit (value depends on the motor)
  motor.setCurrent(100); // 1A current limit
  
  // Set the step mode (microstepping)
  motor.setStepMode(STEP_FS_128); // Full step with 1/128 microstepping
  
  // Enable the motor
  motor.enable();
}

void loop() {
  // Move the motor one step forward
  motor.move(FWD, 1);
  delay(100);
  
  // Move the motor one step backward
  motor.move(REV, 1);
  delay(100);
}

Note: The above code is a simple example to demonstrate basic motor movement. For more advanced features and configurations, refer to the SparkFun AutoDriver library documentation and the L6470 datasheet.