SLOU571 June   2024

 

  1.   1
  2.   Description
  3.   Get Started
  4.   Features
  5.   Applications
  6.   6
  7. 1Evaluation Module Overview
    1. 1.1 Introduction
    2. 1.2 Kit Contents
    3. 1.3 Specification
    4. 1.4 Device Information
  8. 2Hardware
    1. 2.1 EVM Setup and Mode Select
      1. 2.1.1 Jumpers
      2. 2.1.2 DRV8421A: Brushed-DC Setup
      3. 2.1.3 DRV8421A: Stepper Setup
      4. 2.1.4 DRV8421B: Brushed-DC Setup
      5. 2.1.5 DRV8421B: Stepper Setup
      6. 2.1.6 EVM Control
        1. 2.1.6.1 DRV8421A: Brushed-DC Motor Control
        2. 2.1.6.2 DRV8421A: Stepper Motor Control
        3. 2.1.6.3 DRV8421B: Brushed-DC Motor Control
        4. 2.1.6.4 DRV8421B: Stepper Motor Control
      7. 2.1.7 Parallel Mode
        1. 2.1.7.1 DRV8421A: Parallel Mode
        2. 2.1.7.2 DRV8421B: Parallel Mode
      8. 2.1.8 Removing and Installing Supported Motor Drivers
  9. 3Hardware Design Files
    1. 3.1 Schematics
    2. 3.2 PCB (Top-Assembly View)
    3. 3.3 Bill of Materials (BOM)
  10. 4Additional Information
    1. 4.1 Trademarks

2.1.6.4 DRV8421B: Stepper Motor Control

The MSP430 produces PWM signals for the IN1 and IN2 pins with frequencies proportional to the voltage from the MCU Ctrl 1 potentiometer.

MCU Ctrl 1 controls the speed of the stepper motor. Begin with potentiometer fully clockwise and slowly rotate counter-clockwise to increase speed.

DRV8421AEVM, DRV8421BEVM Speed Control Direction Figure 2-12 Speed Control Direction

When operating in Stepper Mode (J2) and the device is Enabled (J1), the speed of the stepper motor is controlled by MCU Ctrl 1 potentiometer. The DRV8421B is configured in a full-step sequence by default and the Step Select (J10) jumper must not be populated.

DRV8421AEVM, DRV8421BEVM EVM Controls for Stepper Motor Operation with DRV8421B Figure 2-13 EVM Controls for Stepper Motor Operation with DRV8421B