SLOU559 April   2023

 

  1.   Abstract
  2.   Trademarks
  3. 1 Introduction
    1. 1.1 DRV8845 Quad H-bridge motor driver
    2. 1.2 DRV8849 Dual Stepper driver
  4. 2 Jumpers Table and Setup
  5. 3 Software Setup
  6. 4 Cloud-based GUI
  7. 5 Local Installation
  8. 6 Hardware Setup
  9. 7 Launching the DRV884x-EVM-GUI Application
  10. 8 GUI Operations DRV8845
  11. 9 GUI Operations DRV8849
  12. 10Updating Firmware
  13. 11Revision History

8 GUI Operations DRV8845

Note: The MSP430 microcontroller used in DRV8845EVM only has two onboard DACs. DAC0 provides microstepping reference voltages VREF1 and VREF3 simultaneously and DAC1 provides microstepping reference voltages VREF2 and VREF4 simultaneously. Because of this limitation while running both stepper motors they will run with the same setting parameters. To run two stepper motors simultaneously with independent control settings, remove the jumper shorts for the required signal inputs and provide control inputs from an external source such as an application microcontroller.
  1. Go to the “Driver Control” tab.
  2. Stepper Motor Control
    1. Select “Stepper Motor Control”.
    2. Set the “Motor Driver” to “Awake” and the required stepper driver outputs to “Enabled”
    3. Select the desired “Control Mode” – This is a GUI app feature which allows selection between “Speed” mode and “Step” mode. In speed mode the motor can run at the set target speed using the defined acceleration and deceleration rate motion profile. In “Step” mode the motor can be stepped to the desired position by setting the required number of steps at the set target speed.
    4. Spinning Two Stepper motors:
      1. Enable Stepper 1 Outputs, then Stepper 2 Outputs. Notice that Stepper 1 Outputs Enabled is greyed out and the Stepper 2 motor controls is greyed out.
      2. Now Stepper 1 Controls is used to control both motors.
      3. Please note that if you start by enabling Stepper 2 Outputs then you are not able to spin two motors.
    5. Features:
      1. Step Mode: Can be used to set the microstepping mode
      2. Full Scale Current: Can be used to set the full scale current value
      3. Starting Speed: The speed at which the motor starts spinning
      4. Target Speed: The final target speed of the motor
      5. Acceleration Rate: Set the acceleration rate at which the motor reaches the target speed
      6. Stopping Speed: Can be used to set the stopping speed of the motor
      7. Number of Steps: Sets the number of steps to cover
      8. Steps to Stop: Sets the number of steps to stop
      9. Fault Clear: used to clear driver faults.
    6. Adjust the settings as needed and select “Start Input Based STEP” to start spinning the motor and use the “Input-based Direction” to change motor direction.
      GUID-20230324-SS0I-N94Q-NX93-CZSTDKZPGZRT-low.png Figure 8-1 Stepper Control in DRV8845-EVM-GUI
      GUID-20230324-SS0I-QN2G-BVCJ-TQKTBRGT4PVL-low.png Figure 8-2 Dual Stepper Control in DRV8845-EVM-GUI
  3. Brushed Motor Control
    1. To switch from “Stepper Motor Control” to “Brushed DC Motor Control”, first disable the stepper outputs and then put the motor driver to “Asleep” state.
    2. Set the “Motor Driver” to “Awake”
    3. Use the VREF1 & VREF3 and VREF3 & VREF4 widget inputs to enter a reference voltage less than or equal to 0.5625 V (0.5625 corresponds to 1.5 A based on the 330 milliohms current sense resistors used in the Rev A EVM hardware – see PWM Current Control section of the device data sheet).
    4. Use PWM Frequency drop down to select the desired PWM frequency.
    5. Select the desired number of Full bridges using the “Start Drive X” tab.
    6. Adjust the speed of the motor using the “Duty Cycle” slider.
    7. Adjust the direction of the motor spinning using the “Direction” tab
    8. The Phase x Ramp rate can be used to set the duty cycle ramp rate to the new set value.
    9. Parallel Mode:
      1. To enter parallel mode:
        1. Put the device to sleep
        2. Turn off power supply (VM)
        3. Disconnect the USB from computer
        4. Remove jumper on PHASE4/STEP1
        5. Populate all jumpers on connector J13
        6. Reconnect USB
        7. Turn on power supply (VM)
        8. Go to Brushed Motor Control
        9. Turn on Motor Driver (awake state)
        10. Enable the Parallel Mode. H3 becomes H3 and H4. Whereas the earlier H4 will be greyed out.
        11. Then connect the BDC motor to Phase 3 (Connecter J3)
      2. To exit parallel mode:
        1. Disable the Parallel Mode
        2. Put Motor Driver to asleep state
        3. Turn off power supply
        4. Disconnect USB
        5. Remove jumpers on J13
        6. Repopulate jumper on Phase4/STEP1
        7. Reconnect USB
        8. Turn on power supply
        9. Put the motor Driver to Awake state
        GUID-20230329-SS0I-4FQ4-BH99-JC313QFGRH6N-low.png Figure 8-3 Parallel Mode Jumpers
        GUID-20230329-SS0I-230R-F7S2-LNPZQKJHVR7F-low.png Figure 8-4 Brushed DC Motor Control in DRV8845-EVM-GUI