Laird Connectivity RM1xx DVK

Overview

Laird Connectivity’s RM1xx is a module which integrates both LoRa and BLE communications, powered by a Nordic Semiconductor nRF51822 ARM Cortex-M0 CPU and on-board Semtech SX1272 LoRa RF chip. This board supports the RM1xx on the RM1xx development board - RM191 for the 915MHz version and RM186 for the 868MHz version.

This development kit has the following features:

  • ADC

  • CLOCK

  • FLASH

  • GPIO

  • I2C

  • NVIC

  • PWM

  • RADIO (Bluetooth Low Energy)

  • RTC

  • Segger RTT (RTT Console)

  • SPI

  • UART

  • WDT

RM1xx development kit (DVK)

Fig. 169 RM1xx development kit (DVK) (Credit: Laird Connectivity)

RM1xx module

Fig. 170 RM1xx module (Credit: Laird Connectivity)

More information about the module can be found on the RM1xx homepage 1.

The Nordic Semiconductor Infocenter 2 contains the processor’s information and the datasheet.

Hardware

The RM1xx has two internal oscillators. The frequency of the slow clock is 32.768KHz. The frequency of the main clock is 16MHz.

Supported Features

The rm1xx_dvk board configuration supports the following hardware features:

Interface

Controller

Driver/Component

ADC

on-chip

adc

CLOCK

on-chip

clock_control

FLASH

on-chip

flash

GPIO

on-chip

gpio

I2C(M)

on-chip

i2c

NVIC

on-chip

arch/arm

PWM

on-chip

pwm

RTC

on-chip

system clock

RTT

Segger

console

SPI(M/S)

on-chip

spi

SPU

on-chip

system protection

UART

on-chip

serial

WDT

on-chip

watchdog

Other hardware features have not been enabled yet for this board. See Nordic Semiconductor Infocenter 2 for a complete list of hardware features.

Connections and IOs

The development board features a Microchip MCP23S08 SPI port expander - note that this is not currently supported in Zephyr.

Refer to the Microchip MCP23S08 datasheet 5 for further details.

Push buttons

  • BUTTON2 = SW0 = P0.05

Internal Memory

EEPROM Memory

A 512KB (4Mb) Adesto AT25DF041B EEPROM is available via SPI for storage of infrequently updated data and small datasets and can be used with the spi-nor driver. Note that the EEPROM shares the same SPI bus as the SX1272 LoRa transceiver so priority access should be given to the LoRa radio.

Refer to the Adesto AT25DF041B datasheet 3 for further details.

LoRa

A Semtech SX1272 transceiver chip is present in the module which can be used in 915MHz LoRa frequency ranges if using an RM191 module or 868MHz LoRa frequency ranges if uses an RM186 module

Refer to the Semtech SX1272 datasheet 4 for further details.

Programming and Debugging

Flashing

Follow the instructions in the Nordic nRF5x Segger J-Link page to install and configure all the necessary software. Further information can be found in Flashing. Then build and flash applications as usual (see Building an Application and Run an Application for more details).

Here is an example for the Hello World application.

First, run your favorite terminal program to listen for output.

$ minicom -D <tty_device> -b 115200

Replace <tty_device> with the port where the board nRF51 DK can be found. For example, under Linux, /dev/ttyACM0.

Then build and flash the application in the usual way.

# From the root of the zephyr repository
west build -b rm1xx_dvk samples/hello_world
west flash

Debugging

Refer to the Nordic nRF5x Segger J-Link page to learn about debugging boards with a Segger IC.

References

1

https://www.lairdconnect.com/wireless-modules/lorawan-solutions/sentrius-rm1xx-lora-ble-module

2(1,2)

https://infocenter.nordicsemi.com

3

https://www.dialog-semiconductor.com/sites/default/files/ds-at25df041b_040.pdf

4

https://semtech.my.salesforce.com/sfc/p/#E0000000JelG/a/440000001NCE/v_VBhk1IolDgxwwnOpcS_vTFxPfSEPQbuneK3mWsXlU

5

https://ww1.microchip.com/downloads/en/DeviceDoc/MCP23008-MCP23S08-Data-Sheet-20001919F.pdf