UM11158
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User manual
Rev. 1.6 — 17 March 2022
18 of 24
NXP Semiconductors
UM11158
LPCXpresso55S69/55S28 Development Boards
Note that jumper J10 may also be used as a convenient way to always assert ISP when
the LPC55Sxx is reset or powered up. This jumper is in parallel with S1.
7.5.2 User (S3) and Wake (S2) buttons
The User (S3) and Wake (S2) buttons are intended for user application use. These
buttons pull ports P1_9 (User) and P1_18 (Wake) low when the button is pressed.
100kohm resistors are used to pull these two ports to VDD then the buttons are not
pressed.
7.5.3 Reset
Pressing this button will assert reset to the LPC55Sxx and to the Mikroe and Arduino
connector sites. Note that the Debug Probe (LPC4322) is not reset when this button is
pressed.
7.6 Crystals
For applications requiring high-speed communication such as high-speed USB and
accurate clock such as real-time clock (RTC), two external crystals are provided on the
board, 16MHz crystal for XTAL32M and 32.768KHz for XTAL32K.
External capacitors are not required on the crystal pins, but are installed on Revision A1
and A2 boards. These may be removed for better performance if issues are observed.
See the “Chapter 12: LPC55S6x/LPC55S2x/LPC552x Cap Bank API” of the
LPC55S6x/LPC55S2x/LPC552x User manual for further information.
8. Expansion
connectors
The LPCXpresso55S69 includes 3 expansion connector sets, incorporating support for
Arduino UNO R3, Mikroe Click and PMod standards. The Arduino UNO connector
footprint is surrounded by additional connectors that are compatible with other
LPCXpresso V3 boards. Pin out diagrams are provided below in
and
For further details, refer to the board schematics.
8.1 Mikroe Click Site
The connectors P23 and P24 provide a Mikroe Click module site for the wide range of
add-on modules available from MikroElektronika. Note that this site shares the same SPI,
I2C and UART connections as the Arduino/LPCXpresso V3 expansion connectors.
8.2 Host / PMod Connector
Connector P20 is a optional connector (not installed by default) which can provide
convenient access for a remote host to the SPI and I2C ports of the LPC55Sxx that
support ISP mode. When setting up the Board to be used with a host, jumper P1 must be
installed to prevent conflict with the Link2 (which can also emulate an SPI or I2C host).
Jumper J4 can be used to force the LPC55Sxx to boot in ISP mode, and connector P14
can be installed and used to provide an external reset control input from the host, The
connector footprint and connection can also be used to connect to external PMod
peripherals that follow the PMod I2C, or SPI (Type 2 or 2A) standards. Refer to the PMod
specifications from Digilent Inc. for more information.