
Table 7. Digital audio amplifier port connections (continued)
Circuit reference
Port
I2S BLCK
P0_7
I2S DAI
P0_9
I2S DAO
P0_23
I2S WS
P0_8
7.3 SD/eMMC card slot
The SD card (J32) included in the MIMXRT685-EVK board provides a 4-bit SDIO interface to support memory cards, plug-in WiFi
modules, etc. Power enable to the socket is provided via
P2_4
.
Software drivers and related examples for the SD card are provided as part of the MCUXpresso SDK.
Table 8. Micro SD card connections
SDIO interface signals
Circuit reference
Port
Notes
SDIO Clock
SD_CLK
P1_30
ICON function 2
SDIO Command
SD_CMD
P1_31
ICON function 2
D0
SD_DAT0
P2_0
ICON function 2
D1
SD_DAT1
P2_1
ICON function 2
D2
SD_DAT2
P2_2
ICON function 2
D3
SD_DAT3
P2_3
ICON function 2
Card detect
SD_CD
P2_9
ICON function 2
Power enable
SD_WR_PRT
P2_4
ICON function 2
For further details, please refer to the boards schematics and SD/MMC chapter on the User Manual.
7.4 Accelerometer
The board includes an NXP FXOS8700CQ accelerometer, interfaced to port 0 (
P0_17
and
P0_18
) with its interrupt output
connected to
P1_5
(JP30 has to be populated). The accelerometer has an I
2
C address of
0b00011110
(
0x1E
). See schematic for
further information. JP15 must be installed to provide voltage supply to the accelerometer.
I
2
C software drivers are provided as part of the MCUXpresso SDK, and example code is provided to illustrate how to read values
from the accelerometer.
7.5 User LEDS
Three user LEDs are provided on the board. The LEDs in this device are controlled by MIMXRT685 ports
P0_26
(Blue),
P0_31
(Red),
P0_14
(Green) with the LEDs being illuminated when the respective led is pulled low.
7.6 Buttons
Four buttons are provided on the MIMXRT685-EVK, as described in this section.
7.6.1 User buttons (SW1 and SW2)
SW1 (
P1_1
) and SW2 (
P0_10
) buttons are intended for user application use. These buttons pull ports low when the button is
pressed. 100 kΩ resistors are used to pull these two ports to
VDDIO1
when the buttons are not pressed.
NXP Semiconductors
On-board peripherals
i.MX RT685 Evaluation Board, Rev. 0, March 20 2020
User's Guide
23 / 31