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UM11158
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2019. All rights reserved.
User manual
Rev. 1.2 — 25 April 2019
16 of 24
NXP Semiconductors
UM11158
LPCXpresso55S69 Development Board
7.2 Micro SD card slot
The micro SD card (P21) included in the LPCXpresso55S69 board provides a 4-bit SDIO
interface to support memory cards, plug-in WiFi modules, etc. Power enable to the socket
is provided via transistor enabled by P1_0.
Software drivers and related examples for the SD card are provided as part of the
MCUXpresso SDK.
7.3 Accelerometer
The board includes an NXP MMA8652FCR1 accelerometer, interfaced to Flexcom 4
(ports P1_21 and P1_20) with its interrupt output connected to P1_19 (this signal is also
shared with the Expansion connector P18 via a 100 ohm resistor (R5).) The
accelerometer has an I2C address of 0b0011101.
Note that the accelerometer can only be used when the board is configured for 3.3V
operation. Resistor R20 may be removed to disconnect the MMA8652 from the supply
rail, and P25 may be installed to provide a convenient way to connect/disconnect it to/from
power.
Resistors R3 and R4 are zero ohm links, provided to enable the MMA8652 to be
disconnected from P1_20 and P1_21 to avoid leakage effects when the board is
configured for 1.8V operation.
I2C software drivers are provided as part of the MCUXpresso SDK, and example code is
provided to illustrate how to read values from the accelerometer.
7.4 RGB User LED
An User controlled RGB LED is provided on the Board, located on the right hand edge.
The LEDs in this device are controlled by LPC55S69 ports P1_4 (Blue), P1_6 (Red), P1_7
(Green) with the LEDs being illuminated when the respective LED is pulled low. Note that
these port lines are also connected to expansion connector J18.
7.5 Buttons
Four buttons are provided on the LPCXpresso55S69, as described in this section.
Table 3.
Micro SD card connections
SDIO interface signals
Port
Notes
SDIO Clock
P0_7
IOCON function 2
SDIO Command
P0_8
IOCON function 2
D0
P0_9
IOCON function 2
D1
P0_17
IOCON function 2
D2
P0_24
IOCON function 2
D3
P0_25
IOCON function 2
Card detect
P0_21
IOCON function 2
Power enable
P1_0
GPIO. Active low.