
3 Software
3.1 Firmware and GUI Application
The MCT8314ZEVM includes a USB-to-UART interface, using a MSP4302355 microcontroller, that serves as a
communication bridge between a host PC and the MCT8314Z device for configuring various device settings and
reading fault diagnostic information. The MCT8314Z GUI is available to monitor the motor the MCT8314Z device
and in the case of the MCT8314ZS configure the device.
The MCT8314Z GUI is available on the dev.ti.com/gallery. The MCT8314Z GUI supports all variants of the
MCT8314Z. The MCT8314Z GUI is able to measure the speed of the motor by monitoring the duty cycle of the
20-kHz PWM waveform and the frequency of the FGOUT output. Providing the number of poles the motor has to
the GUI, the GUI calculates the speed of the motor in revolutions per minute (RPM). The GUI also allows for the
ability to control the nSLEEP signal to put the MCT8314Z into a low power sleep mode. For the MCT8314ZS the
GUI also includes a register map and the ability to read and write over SPI to configure the devices registers.
By default, the MSP430 already contains the firmware required for the EVM to be able to connect and
communicate with the MCT8314Z GUI. If there is a FW update or the GUI does not connect to the EVM then the
user must flash the code onto the MSP430.
Flashing the firmware onto the EVM requires an external MSP430 LaunchPad™ that includes the eZ-FET
Debug Probe and Code Composer Studio™ (CCS). The example in Section 3.4 uses the MSP-EXP430FR2355
LaunchPad Development Kit to provide the eZ-FET Debug Probe.
3.2 MCT8314Z GUI
The following features are enabled in the MCT8314Z GUI:
PWM or Duty Cycle Settings
• Use the R6 potentiometer on the MCT8314ZEVM to control the duty cycle of the 20-kHz PWM waveform
from the MSP430FR2355. The slider and gauge updates real-time with the duty cycle from 0–100%.
Motor Settings and Calculations
• Update the number of motor poles in the motor using the Motor Poles drop-down box.
• The FGOUT frequency is measured and updated real time in the FGOUT Freq (Hz) box.
• The value in the FGOUT freq. (Hz) and Motor poles boxes are used to calculate and update the value in the
Motor Speed (RPM) box. The value for the RPM speed is calculated by the formula in Equation 1. Note that
the FGOUT frequency is multiplied by 120 to achieve the frequency of one electrical cycle, in Hz.
1 MotorSpeedRPM =120 × FGOUT
# MotorPoles (1)
Status LEDs and nSLEEP Control
• The status of the programmable MCU LEDs are shown by LED1 and LED2.
• To place the MCT8314Z into a low-power sleep mode, click the nSLEEP button into the right position. This
causes the MSP430 to send an active-low signal to nSLEEP on the device.
Software www.ti.com
14 MCT8314Z Evaluation Module SNLU341 – DECEMBER 2023
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