NXP LPCXpresso55S28

Overview

The LPCXpresso55S28 development board provides the ideal platform for evaluation of and development with the LPC552x/S2x MCU based on the Arm® Cortex®-M33 architecture. The board includes a high-performance onboard debug probe, audio subsystem and accelerometer, with several options for adding off-the-shelf add-on boards for networking, sensors, displays, and other interfaces.

Hardware

• LPC55S28 Arm® Cortex®-M33 microcontroller running at up to 150 MHz

• 512 KB flash and 256 KB SRAM on-chip

• Onboard, high-speed USB, Link2 debug probe with CMSIS-DAP and SEGGER J-Link protocol options

• UART and SPI port bridging from LPC55S28 target to USB via the onboard debug probe

• Hardware support for external debug probe

• 3 x user LEDs, plus Reset, ISP (3) and user buttons

• Micro SD card slot (4-bit SDIO)

• NXP MMA8652FCR1 accelerometer

• Stereo audio codec with line in/out

• High and full speed USB ports with micro A/B connector for host or device functionality

• MikroEletronika Click expansion option

• LPCXpresso-V3 expansion option compatible with Arduino UNO

• PMod compatible expansion / host connector

For more information about the LPC55S28 SoC and LPCXPresso55S28 board, see:

• LPC55S28 SoC Website

• LPC55S28 Datasheet

• LPC55S28 User Manual

• LPCXpresso55S28 Website

• LPCXpresso55S28 User Manual

• LPCXpresso55S28 Development Board Design Files

Supported Features

The lpcxpresso55s28 board configuration supports the hardware features listed below. For additional features not yet supported, please also refer to the NXP LPCXPRESSO55S69 , which is the superset board in NXP’s LPC55xx series. NXP prioritizes enabling the superset board with NXP’s Full Platform Support for Zephyr. Therefore, the lpcxpresso55s69 board may have additional features already supported, which can also be re-used on this lpcxpresso55s28 board:

Interface	Controller	Driver/Component
NVIC	on-chip	nested vector interrupt controller
SYSTICK	on-chip	systick
IOCON	on-chip	pinmux
GPIO	on-chip	gpio
I2C	on-chip	i2c
SPI	on-chip	spi
USART	on-chip	serial port-polling; serial port-interrupt
WWDT	on-chip	windowed watchdog timer
ADC	on-chip	adc
CLOCK	on-chip	clock_control
RNG	on-chip	entropy; random
IAP	on-chip	flash programming

Other hardware features are not currently enabled.

The default configuration file boards/arm/lpcxpresso55s28/lpcxpresso55s28_defconfig

Connections and IOs

The LPC55S28 SoC has IOCON registers, which can be used to configure the functionality of a pin.

Name	Function	Usage
PIO0_26	SPI	SPI MOSI
PIO0_29	USART	USART RX
PIO0_30	USART	USART TX
PIO1_1	SPI	SPI SSEL
PIO1_2	SPI	SPI SCK
PIO1_3	SPI	SPI MISO
PIO1_4	GPIO	RED LED
PIO1_6	GPIO	BLUE_LED
PIO1_7	GPIO	GREEN LED
PIO1_20	I2C	I2C SCL
PIO1_21	I2C	I2C SDA

System Clock

The LPC55S28 SoC is configured to use the internal FRO at 96MHz as a source for the system clock. Other sources for the system clock are provided in the SOC, depending on your system requirements.

Serial Port

The LPC55S28 SoC has 8 FLEXCOMM interfaces for serial communication. One is configured as USART for the console and the remaining are not used.

Programming and Debugging

Build and flash applications as usual (see Building an Application and Run an Application for more details).

Configuring a Debug Probe

A debug probe is used for both flashing and debugging the board. This board is configured by default to use the LPC-Link2 CMSIS-DAP Onboard Debug Probe.

Configuring a Console

Connect a USB cable from your PC to P6, and use the serial terminal of your choice (minicom, putty, etc.) with the following settings:

• Speed: 115200

• Data: 8 bits

• Parity: None

• Stop bits: 1

Flashing

Here is an example for the Hello World application.

# From the root of the zephyr repository
west build -b lpcxpresso55s28 samples/hello_world
west flash

Open a serial terminal, reset the board (press the RESET button), and you should see the following message in the terminal:

***** Booting Zephyr OS v2.4.0 *****
Hello World! lpcxpresso55s28

Debugging

Here is an example for the Hello World application.

# From the root of the zephyr repository
west build -b lpcxpresso55s28 samples/hello_world
west debug

Open a serial terminal, step through the application in your debugger, and you should see the following message in the terminal:

***** Booting Zephyr OS zephyr-v2.4.0 *****
Hello World! lpcxpresso55s28