LoRa-E5 mini

Overview

LoRa-E5 mini is a compacted-sized development board suitable for the rapid testing and building of small-sized LoRa device, exposing all capabilities of Seeed Studio LoRa-E5 STM32WLE5JC module.

Hardware

The boards’ LoRa-E5 Module packages a STM32WLE5JC SOC, a 32MHz TCXO, and a 32.768kHz crystal oscillator in a 28-pin SMD package. This STM32WLEJC SOC is powered by ARM Cortex-M4 core and integrates Semtech SX126X LoRa IP to support (G)FSK, BPSK, (G)MSK, and LoRa modulations.

  • LoRa-E5 STM32WLE5JC Module with STM32WLE5JC multiprotocol LPWAN single-core 32-bit microcontroller (Arm® Cortex®-M4 at 48 MHz) in 28-pin SMD package featuring:

    • Ultra-low-power MCU

    • RF transceiver (150 MHz to 960 MHz frequency range) supporting LoRa®, (G)FSK, (G)MSK, and BPSK modulations

    • 256-Kbyte Flash memory and 64-Kbyte SRAM

    • Hardware encryption AES256-bit and a True random number generator

  • 1 user LED

  • 2 serial communication (RX/TX) LEDs

  • 1 boot/user and 1 reset push-button

  • 32.768 kHz LSE crystal oscillator

  • 32 MHz HSE oscillator

  • Board connectors:

    • USB Type-C connector

    • +/- (battery) power input pins (3-5V)

    • SMA-K and IPEX antenna connectors

  • Delivered with SMA antenna (per default IPEX connector is disconnected)

  • Flexible power-supply options: USB Type C or 3-5V battery soldered to +/- pins

  • Suitable for rapid prototyping of end nodes based on LoRaWAN, Sigfox, wM-Bus, and many other proprietary protocols

  • All GPIOs led out from the LoRa-E5 STM32WLE5JC module

  • 4x M2 mounting holes

More information about the board can be found at the LoRa-E5 mini Wiki.

More information about LoRa-E5 STM32WLE5JC Module can be found here:

Supported Features

The lora_e5_mini 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.

lora_e5_mini/stm32wle5xx target

Type

Location

Description

Compatible

CPU

on-chip

ARM Cortex-M4 CPU1

arm,cortex-m4

ADC

on-chip

STM32 ADC1

st,stm32-adc

Clock control

on-chip

STM32WL RCC (Reset and Clock controller)1

st,stm32wl-rcc

on-chip

STM32WL HSE Clock1

st,stm32wl-hse-clock

on-chip

Generic fixed-rate clock provider1 1

fixed-clock

on-chip

STM32 MSI Clock1

st,stm32-msi-clock

on-chip

STM32 LSE Clock1

st,stm32-lse-clock

on-chip

STM32WB and STM32WL PLL node1

st,stm32wb-pll-clock

on-chip

STM32 Microcontroller Clock Output (MCO)1

st,stm32-clock-mco

Counter

on-chip

STM32 counters3

st,stm32-counter

Cryptographic accelerator

on-chip

STM32 AES Accelerator1

st,stm32-aes

DAC

on-chip

STM32 family DAC1

st,stm32-dac

DMA

on-chip

STM32 DMA controller (V2)2

st,stm32-dma-v2

on-chip

STM32 DMAMUX controller1

st,stm32-dmamux

Flash controller

on-chip

STM32 Family flash controller1

st,stm32-flash-controller

GPIO & Headers

on-chip

STM32 GPIO Controller4

st,stm32-gpio

I2C

on-chip

STM32 I2C V2 controller1 2

st,stm32-i2c-v2

Input

on-board

Group of GPIO-bound input keys1

gpio-keys

Interrupt controller

on-chip

ARMv7-M NVIC (Nested Vectored Interrupt Controller)1

arm,v7m-nvic

on-chip

STM32 External Interrupt Controller1

st,stm32-exti

LED

on-board

Group of GPIO-controlled LEDs1

gpio-leds

LoRa

on-chip

STM32WL Sub-GHz Radio1

st,stm32wl-subghz-radio

Memory controller

on-chip

STM32 Battery Backed RAM1

st,stm32-bbram

MTD

on-chip

STM32 flash memory1

st,stm32-nv-flash

on-board

Fixed partitions of a flash (or other non-volatile storage) memory1

fixed-partitions

Pin control

on-chip

STM32 Pin controller1

st,stm32-pinctrl

Power management

on-chip

STM32 power controller1

st,stm32-pwr

PWM

on-chip

STM32 PWM4

st,stm32-pwm

Reset controller

on-chip

STM32 Reset and Clock Control (RCC) Controller1

st,stm32-rcc-rctl

RNG

on-chip

STM32 Random Number Generator1

st,stm32-rng

RTC

on-chip

STM32 RTC1

st,stm32-rtc

Sensors

on-chip

STM32 family TEMP node for production calibrated sensors with two calibration temperatures1

st,stm32-temp-cal

on-chip

STM32 VREF+1

st,stm32-vref

on-chip

STM32 VBAT1

st,stm32-vbat

Serial controller

on-chip

STM32 USART1 1

st,stm32-usart

on-chip

STM32 LPUART1

st,stm32-lpuart

SMbus

on-chip

STM32 SMBus controller3

st,stm32-smbus

SPI

on-chip

STM32 SPI controller with embedded Rx and Tx FIFOs2

st,stm32-spi-fifo

on-chip

STM32 SUBGHZ SPI controller1

st,stm32-spi-subghz

SRAM

on-chip

Generic on-chip SRAM description1

mmio-sram

Timer

on-chip

ARMv7-M System Tick1

arm,armv7m-systick

on-chip

STM32 low-power timer (LPTIM)1

st,stm32-lptim

on-chip

STM32 timers4

st,stm32-timers

Watchdog

on-chip

STM32 watchdog1

st,stm32-watchdog

on-chip

STM32 system window watchdog1

st,stm32-window-watchdog

Connections and IOs

LoRa-E5 mini has 4 GPIO controllers. These controllers are responsible for pin muxing, input/output, pull-up, etc.

Available pins:

LoRa-E5 mini Pinout

Default Zephyr Peripheral Mapping:

  • USART_1 TX : PB6

  • USART_1 RX : PB7

  • I2C_2_SCL : PB15

  • I2C_2_SDA : PA15

  • BOOT_PB : PB13

  • LED_1 : PB5

System Clock

LoRa-E5 mini board System Clock could be driven by the low-power internal (MSI), High-speed internal (HSI) or High-speed external (HSE) oscillator, as well as main PLL clock. By default System clock is driven by the MSI clock at 48MHz.

Programming and Debugging

Applications for the lora_e5_mini board configuration can be built the usual way (see Building an Application).

In the factory the module is flashed with an DFU bootloader, an AT command firmware, and the read protection level 1 is enabled. So before you can program a Zephyr application to the module for the first time you have to reset the read protection to level 0. In case you use an st-link debugger you can use the STM32CubeProgrammer GUI to set the RDP option byte to AA, or use the STM32_Programmer_CLI passing the --readunprotect command to perform this read protection regression. The RDP level 1 to RDP level 0 regression will erase the factory programmed AT firmware, from which seeed studio has neither released the source code nor a binary. Also, note that on the module the BOOT0 pin of the SOC is not accessible, so the system bootloader will only be executed if configured in the option bytes.

Flashing

The LoRa-E5 mini does not include a on-board debug probe. But the module can be debugged by connecting an external debug probe to the 2.54mm header. Depending on the external probe used, openocd, the stm32cubeprogrammer, pyocd, blackmagic, or jlink runner can be used to flash the board. Additional notes:

  • Pyocd: For STM32WL support Pyocd needs additional target information, which can be installed by adding “pack” support with the following pyocd command:

$ pyocd pack --update
$ pyocd pack --install stm32wl

Flashing an application to LoRa-E5 mini

Connect the LoRa-E5 to your host computer using the external debug probe. Then build and flash an application. Here is an example for the Hello World application.

Run a serial host program to connect with your board: Per default the console on usart1 is available on the USB Type C connector via the built-in USB to UART converter.

$ picocom --baud 115200 /dev/ttyACM0

Then build and flash the application.

# From the root of the zephyr repository
west build -b lora_e5_mini samples/hello_world
west flash

Debugging

You can debug an application in the usual way. Here is an example for the Blinky application.

# From the root of the zephyr repository
west build -b lora_e5_mini samples/basic/blinky
west debug