Texas Instruments DRV814x-Q1EVM, User Manual, Page: 6 / 22

A jumper should be installed shorting pins 1 and 2 on header J1 for the MCU reset function. If a firmware reset
is necessary, the push button is pressed once and released. Following a reset, a proper startup is indicated by
the blinking STATUS LED. If the jumper is moved to pins 2 and 3 on J1, this routes the button to a spare GPIO
pin on the MSP430 MCU, and can be used for your own purposes in the firmware. Beginning with version 0.22
of the firmware, an interrupt subroutine (ISR) has been assigned to this GPIO input, and will automatically put
the DRV824x device in PH/EN mode, and energize the output OUT1 terminal (or OUT terminal of the DRV814x
device) at 25% duty cycle on the first press of the User button with a 12 V power supply connected to the
connector J14, BAT+ and GND screw terminals. Pressing the button again will disable the output. This can be
repeated with the same on/ off behavior. This can be useful as a quick out-of-box test of the EVM without a
computer or USB connection. You can connect a brushed DC motor across OUT1 and OUT2 terminals of the
DRV824x EVM or OUT and GND of the DRV814x EVM, or simply an oscilloscope.
Note
No diagnostics are enabled in this simple test case – open load detection is not active
When in this test mode, the STATUS LED (D1) will be fully on when the output is active, and will return to
approximately 1 Hz blinking when the output is off with an SPI EVM or an approximately 0.1 Hz blinking with
an HW EVM. After completion of the standalone EVM testing it is recommended to position the jumper settings
back to pins 1 and 2.
Figure 3-2. MCU Reset and User Button
3.2.3 Communication Interfaces
The micro-USB connection is the primary communication interface from your PC to the EVM GUI Application.
Figure 3-3 illustrates connection associated with communications between the EVM and GUI, as well as
firmware programming (some components have been removed from the picture for clarity).
Evaluation Hardware Overview www.ti.com
6 DRV824x_DRV814x-Q1EVM User’s Guide SLVUC46A – MARCH 2021 – REVISED JULY 2021
Submit Document Feedback
Copyright © 2021 Texas Instruments Incorporated