How to Use DRV8835 Shield Carrier: Examples, Pinouts, and Specs

The DRV8835 Shield Carrier, manufactured by Pololu (Part ID: DRV8835), is a compact and efficient motor driver shield designed for controlling DC motors and stepper motors. It features dual H-bridge outputs, enabling bidirectional control and speed regulation. This shield is ideal for low-voltage motor control applications and is compatible with microcontroller platforms like Arduino.

• Robotics: Driving small DC motors for wheels or actuators.
• Automation: Controlling stepper motors in precision systems.
• DIY Projects: Building motorized mechanisms such as conveyor belts or robotic arms.
• Educational Projects: Learning motor control and PWM (Pulse Width Modulation) techniques.

The DRV8835 Shield Carrier is designed to provide reliable motor control with the following specifications:

The DRV8835 Shield Carrier has the following pin layout:

1. Power Supply: Connect the motor power supply to the VIN pin (2 V to 11 V) and ground to the GND pin. Ensure the supply voltage matches the motor's requirements.
2. Logic Voltage: Provide a logic voltage (1.8 V to 7 V) to the VCC pin. This is typically supplied by the microcontroller.
3. Motor Connections: Connect the motors to the M1A, M1B, M2A, and M2B pins. For a single stepper motor, use both channels.
4. Control Pins: Use the DIR1, PWM1, DIR2, and PWM2 pins to control motor direction and speed. These pins can be connected to a microcontroller's GPIO or PWM outputs.

• Heat Dissipation: The DRV8835 can handle high currents, but prolonged operation at maximum current may cause overheating. Ensure proper ventilation or heat sinking if necessary.
• Voltage Matching: Verify that the motor voltage and current ratings are within the DRV8835's operating range.
• PWM Frequency: Use a PWM frequency between 20 kHz and 100 kHz for optimal performance and minimal audible noise.
• Reverse Polarity Protection: The shield does not include reverse polarity protection. Double-check connections before powering the circuit.

The following example demonstrates how to control two DC motors using the DRV8835 Shield Carrier with an Arduino UNO.

// DRV8835 Motor Driver Example Code for Arduino UNO
// This code controls two DC motors using PWM and direction pins.

#define DIR1 7  // Direction pin for Motor 1
#define PWM1 6  // PWM pin for Motor 1
#define DIR2 4  // Direction pin for Motor 2
#define PWM2 5  // PWM pin for Motor 2

void setup() {
  // Set motor control pins as outputs
  pinMode(DIR1, OUTPUT);
  pinMode(PWM1, OUTPUT);
  pinMode(DIR2, OUTPUT);
  pinMode(PWM2, OUTPUT);
}

void loop() {
  // Motor 1: Forward at 50% speed
  digitalWrite(DIR1, HIGH);  // Set direction forward
  analogWrite(PWM1, 128);    // Set speed (0-255, 128 = 50%)

  // Motor 2: Reverse at 75% speed
  digitalWrite(DIR2, LOW);   // Set direction reverse
  analogWrite(PWM2, 192);    // Set speed (0-255, 192 = 75%)

  delay(2000);  // Run motors for 2 seconds

  // Stop both motors
  analogWrite(PWM1, 0);
  analogWrite(PWM2, 0);

  delay(1000);  // Wait for 1 second before repeating
}

1. Motors Not Running:

   • Verify that the power supply is connected and within the specified voltage range.
   • Check the motor connections to the M1A, M1B, M2A, and M2B pins.
   • Ensure the control pins (DIR and PWM) are correctly configured in the code.

2. Overheating:

   • Reduce the motor load or operating current.
   • Add a heat sink or improve ventilation around the shield.

3. Erratic Motor Behavior:

   • Check for loose or faulty connections.
   • Ensure the PWM frequency is within the recommended range (20 kHz to 100 kHz).

4. No Response from Shield:

   • Confirm that the logic voltage (VCC) is supplied and matches the microcontroller's logic level.
   • Test the control pins with a multimeter to ensure proper signal output.

Q: Can the DRV8835 Shield Carrier drive stepper motors?
A: Yes, the DRV8835 can drive a single bipolar stepper motor by using both motor channels. Ensure proper wiring and control sequencing.

Q: What is the maximum current the DRV8835 can handle?
A: The DRV8835 can handle up to 1.2 A continuously per channel and 1.5 A peak for short durations.

Q: Is the shield compatible with 3.3 V logic microcontrollers?
A: Yes, the DRV8835 supports logic voltages as low as 1.8 V, making it compatible with 3.3 V and 5 V systems.

Q: Can I use the shield with a Raspberry Pi?
A: Yes, the DRV8835 can be controlled by a Raspberry Pi, but additional software libraries may be required for PWM control.