How to Use MP6500: Examples, Pinouts, and Specs

The MP6500 is a high-performance stepper motor driver manufactured by Pololu. It is designed to provide precise control of stepper motors, making it ideal for applications requiring smooth and accurate motion. The MP6500 supports adjustable current control, microstepping capabilities, and includes built-in protection features such as overcurrent, overtemperature, and undervoltage lockout. These features make it a versatile and reliable choice for robotics, 3D printing, CNC machines, and other automation systems.

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

• Operating Voltage Range: 4.5 V to 35 V
• Output Current: Up to 1.5 A continuous per phase (with sufficient cooling)
• Microstepping: Full-step, half-step, 1/4-step, 1/8-step, 1/16-step
• Logic Voltage: 1.8 V to 5 V
• Current Control: Adjustable via potentiometer
• Protection Features: Overcurrent, overtemperature, and undervoltage lockout
• Dimensions: 15.2 mm × 20.3 mm

The MP6500 stepper motor driver has 16 pins. Below is the pin configuration and description:

1. Power Connections:

   • Connect the motor power supply (4.5 V to 35 V) to the VM pin.
   • Connect the ground of the motor power supply and logic supply to the GND pin.
   • Connect the logic voltage (1.8 V to 5 V) to the VCC pin.

2. Motor Connections:

   • Connect the two terminals of motor coil A to OUT1A and OUT1B.
   • Connect the two terminals of motor coil B to OUT2A and OUT2B.

3. Control Signals:

   • Use the STEP pin to control the motor's steps. Each rising edge advances the motor by one step.
   • Use the DIR pin to set the motor's rotation direction (logic high or low).
   • Configure the microstepping mode using the MS1 and MS2 pins:
     • MS1 = 0, MS2 = 0: Full-step
     • MS1 = 1, MS2 = 0: Half-step
     • MS1 = 0, MS2 = 1: 1/4-step
     • MS1 = 1, MS2 = 1: 1/8-step or 1/16-step (depending on the version of the MP6500).

4. Adjusting Current Limit:

   • Use the onboard potentiometer to set the current limit. This protects the motor and driver from overheating.
   • Calculate the reference voltage (VREF) using the formula:

     Current Limit (A) = VREF / (8 × RS)
     

     where RS is the sense resistor value (typically 0.1 Ω for the MP6500).

5. Enable and Sleep Modes:

   • Pull the ENABLE pin low to enable the driver.
   • Pull the SLEEP pin low to put the driver into low-power sleep mode.

Below is an example of how to control the MP6500 with an Arduino UNO:

// Define pin connections
#define STEP_PIN 3  // Connect to the STEP pin of the MP6500
#define DIR_PIN 4   // Connect to the DIR pin of the MP6500

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 = one direction)
}

void loop() {
  // Generate step pulses to move the motor
  digitalWrite(STEP_PIN, HIGH); // Set STEP pin HIGH
  delayMicroseconds(1000);      // Wait 1 ms (adjust for speed control)
  digitalWrite(STEP_PIN, LOW);  // Set STEP pin LOW
  delayMicroseconds(1000);      // Wait 1 ms
}

• Ensure the motor power supply voltage matches the motor's specifications.
• Adjust the current limit to prevent overheating of the motor and driver.
• Use adequate cooling (e.g., a heat sink) if operating near the maximum current rating.
• Avoid connecting or disconnecting the motor while the driver is powered to prevent damage.

1. Motor Not Moving:

   • Verify all connections, especially the motor coils and power supply.
   • Check the STEP and DIR signals from the microcontroller.
   • Ensure the ENABLE pin is pulled low.

2. Driver Overheating:

   • Reduce the current limit using the potentiometer.
   • Add a heat sink or improve ventilation.

3. Fault Pin is Low:

   • Check for overcurrent or short circuits in the motor connections.
   • Ensure the motor power supply voltage is within the specified range.

4. Erratic Motor Movement:

   • Verify the microstepping mode configuration (MS1 and MS2 pins).
   • Ensure the STEP signal timing is consistent and within the driver's specifications.

Q: Can I use the MP6500 with a 12 V stepper motor?
A: Yes, the MP6500 supports a wide voltage range (4.5 V to 35 V). Ensure the motor power supply matches the motor's voltage rating.

Q: How do I calculate the current limit for my motor?
A: Use the formula:

Current Limit (A) = VREF / (8 × RS)

Adjust the potentiometer to set the desired VREF.

Q: What happens if I exceed the current limit?
A: The MP6500 includes overcurrent protection and will shut down to prevent damage. Reduce the current limit or improve cooling.

Q: Can I use the MP6500 with a 3.3 V microcontroller?
A: Yes, the MP6500 supports logic voltages from 1.8 V to 5 V, making it compatible with 3.3 V systems.