XIAO nRF54LM20A

Overview

Seeed Studio XIAO nRF54LM20A is a compact, high-performance development board featuring the Nordic nRF54LM20A chip. This SoC integrates an ultra-low power multiprotocol 2.4 GHz radio and an MCU with a 128 MHz Arm(R) Cortex(R)-M33 processor and a RISC-V Fast Lightweight Peripheral Processor (FLPR) coprocessor. It offers 1.5 MB RRAM and 512 KB RAM.

The board features a built-in PMIC (Nordic NPM1300) with battery charging support, an RGB LED, an LSM6DS3TR-C 6-axis IMU, USB HS, NFCT, and an external SPI flash (PY25Q64HA, 64 Mbit). The XIAO form factor provides 28 pins (D0-D27) with support for GPIO, I2C, SPI, UART, ADC, PWM, and more.

Designed for exceptional ultra-low power consumption, it significantly extends battery life. Its robust radio supports Bluetooth(R), Matter, Thread, Zigbee, and a high-throughput 2.4 GHz proprietary mode. The board is ideal for compact, secure, and energy-efficient IoT solutions such as smart wearables, industrial sensors, and advanced human-machine interfaces.

Hardware

  • 128 MHz Arm(R) Cortex(R)-M33 processor

  • RISC-V FLPR coprocessor for peripheral processing

  • 1.5 MB RRAM (non-volatile memory)

  • 512 KB RAM

  • Multiprotocol 2.4 GHz radio supporting Bluetooth Low Energy, 802.15.4-2020, and 2.4 GHz proprietary modes

  • Comprehensive set of peripherals including 14-bit ADC, high-speed serial interfaces, PDM/DMIC, and PWM

  • Built-in PMIC (Nordic NPM1300) with battery charging

  • RGB LED (blue, red, green)

  • LSM6DS3TR-C 6-axis IMU (accelerometer + gyroscope)

  • USB HS

  • NFCT (Near Field Communication)

  • External SPI flash (PY25Q64HA, 64 Mbit)

  • 28-pin XIAO connector (D0-D27)

  • Advanced security including TrustZone(R) isolation and cryptographic engine protection

For more information about the nRF54LM20A SoC and XIAO nRF54LM20A board, refer to these documents:

Supported Features

The xiao_nrf54lm20a board supports the hardware features listed below.

on-chip / on-board
Feature integrated in the SoC / present on the board.
2 / 2
Number of instances that are enabled / disabled.
Click on the label to see the first instance of this feature in the board/SoC DTS files.
vnd,foo
Compatible string for the Devicetree binding matching the feature.
Click on the link to view the binding documentation.

Connections and IOs

In the following table, the column Name contains Pin names. For example, P1_0 means Pin number 0 on PORT1, as used in the board’s datasheets and manuals.

Name

Function

Usage

P1_22

GPIO

LED0 (Blue)

P1_23

GPIO

LED1 (Red)

P1_24

GPIO

LED2 (Green)

P0_9

GPIO

Button 0

P1_11

USART20_TX

UART Console TX

P1_10

USART20_RX

UART Console RX

P1_8

USART21_TX

XIAO Serial TX

P1_9

USART21_RX

XIAO Serial RX

P1_3

TWIM22_SDA

XIAO I2C SDA

P1_7

TWIM22_SCL

XIAO I2C SCL

P1_4

SPIM23_SCK

XIAO SPI SCK

P1_6

SPIM23_MOSI

XIAO SPI MOSI

P1_5

SPIM23_MISO

XIAO SPI MISO

P0_8

TWIM30_SDA

IMU I2C SDA

P0_7

TWIM30_SCL

IMU I2C SCL

P1_0

GPIO

XIAO D0

P1_31

GPIO

XIAO D1

P1_30

GPIO

XIAO D2

P1_29

GPIO

XIAO D3

P1_3

GPIO

XIAO D4

P1_7

GPIO

XIAO D5

P1_8

GPIO

XIAO D6

P1_9

GPIO

XIAO D7

P1_4

GPIO

XIAO D8

P1_5

GPIO

XIAO D9

P1_6

GPIO

XIAO D10

P1_12

GPIO

Power Enable

P1_15

GPIO

PMIC I2C SDA

P1_16

GPIO

PMIC I2C SCL

P1_13

PDM20_CLK

DMIC Clock

P1_14

PDM20_DIN

DMIC Data

P2_1

SPIM00_SCK

External SPI Flash SCK

P2_2

SPIM00_MOSI

External SPI Flash MOSI

P2_4

SPIM00_MISO

External SPI Flash MISO

Programming and Debugging

The xiao_nrf54lm20a board supports the runners and associated west commands listed below.

flash debug

The XIAO nRF54LM20A contains a SAMD11 with CMSIS-DAP, allowing flashing, debugging, logging, etc. over the USB port.

Flashing

Connect the XIAO nRF54LM20A board to your host computer using the USB port. A USB CDC ACM serial port should appear on the host, that can be used to view logs from the flashed application.

Here is an example for the Hello World application.

# From the root of the zephyr repository
west build -b xiao_nrf54lm20a/nrf54lm20a/cpuapp samples/hello_world
west flash

Open a serial terminal (minicom, putty, etc.) connecting to the USB CDC ACM serial port.

Reset the board and you should see the following message in the terminal:

Hello World! xiao_nrf54lm20a/nrf54lm20a/cpuapp