B-L072Z-LRWAN1 Discovery kit

Overview

This Discovery kit features an all-in-one open module CMWX1ZZABZ-091 (by Murata). The module is powered by an STM32L072CZ and an SX1276 transceiver.

This kit provides:

CMWX1ZZABZ-091 LoRa* / Sigfox* module (Murata)
- Embedded ultra-low-power STM32L072CZ Series MCUs, based on Arm* Cortex* -M0+ core, with 192 Kbytes of Flash memory, 20 Kbytes of RAM, 6 Kbytes of EEPROM
- Frequency range: 860 MHz - 930 MHz
- USB 2.0 FS
- 4-channel,12-bit ADC, 2xDAC
- 6-bit timers, LP-UART, I2C and SPI
- Embedded SX1276 transceiver
- LoRa* , FSK, GFSK, MSK, GMSK and OOK modulations (+ Sigfox* compatibility)
- +14 dBm or +20 dBm selectable output power
- 157 dB maximum link budget
- Programmable bit rate up to 300 kbit/s
- High sensitivity: down to -137 dBm
- Bullet-proof front end: IIP3 = -12.5 dBm
- 89 dB blocking immunity
- Low Rx current of 10 mA, 200 nA register retention
- Fully integrated synthesizer with a resolution of 61 Hz
- Built-in bit synchronizer for clock recovery
- Sync word recognition
- Preamble detection
- 127 dB+ dynamic range RSSI
SMA and U.FL RF interface connectors
Including 50 ohm SMA RF antenna
On-board ST-LINK/V2-1 supporting USB re-enumeration capability
USB ST-LINK functions:
Board power supply:
- Through USB bus or external VIN/3.3 V supply voltage or batteries
3xAAA-type-battery holder for standalone operation
7 LEDs:
- 4 general-purpose LEDs
- A 5 V-power LED
- An ST-LINK-communication LED
- A fault-power LED
- 2 push-buttons (user and reset)
Arduino* Uno V3 connectors

More information about the board can be found at the B-L072Z-LRWAN1 website.

Hardware

The STM32L072CZ SoC provides the following hardware IPs:

Ultra-low-power (down to 0.29 µA Standby mode and 93 uA/MHz run mode)
Core: ARM* 32-bit Cortex*-M0+ CPU, frequency up to 32 MHz
Clock Sources:
- 1 to 32 MHz crystal oscillator
- 32 kHz crystal oscillator for RTC (LSE)
- Internal 16 MHz factory-trimmed RC ( ±1%)
- Internal low-power 37 kHz RC ( ±5%)
- Internal multispeed low-power 65 kHz to 4.2 MHz RC
RTC with HW calendar, alarms and calibration
Up to 24 capacitive sensing channels: support touchkey, linear and rotary touch sensors
11x timers:
- 2x 16-bit with up to 4 channels
- 2x 16-bit with up to 2 channels
- 1x 16-bit ultra-low-power timer
- 1x SysTick
- 1x RTC
- 2x 16-bit basic for DAC
- 2x watchdogs (independent/window)
Up to 84 fast I/Os, most 5 V-tolerant.
Memories
- Up to 192 KB Flash, 2 banks read-while-write, proprietary code readout protection
- Up to 20 KB of SRAM
- External memory interface for static memories supporting SRAM, PSRAM, NOR and NAND memories
Rich analog peripherals (independent supply)
- 1x 12-bit ADC 1.14 MSPS
- 2x 12-bit DAC
- 2x ultra-low-power comparators
11x communication interfaces
- USB 2.0 full-speed device, LPM and BCD
- 3x I2C FM+(1 Mbit/s), SMBus/PMBus
- 4x USARTs (ISO 7816, LIN, IrDA, modem)
- 6x SPIs (4x SPIs with the Quad SPI)
7-channel DMA controller
True random number generator
CRC calculation unit, 96-bit unique ID
Development support: serial wire debug (SWD), JTAG, Embedded Trace Macrocell*

More information about STM32L072CZ can be found here:

Supported Features

The b_l072z_lrwan1 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.

b_l072z_lrwan1

/

stm32l072xx

Type	Location	Description	Compatible
CPU	on-chip	ARM Cortex-M0+ CPU1	`arm,cortex-m0+`
ADC	on-chip	STM32 ADC1	`st,stm32-adc`
Clock control	on-chip	STM32 RCC (Reset and Clock controller)1	`st,stm32-rcc`
	on-chip	STM32 HSE Clock1	`st,stm32-hse-clock`
	on-chip	Generic fixed-rate clock provider2 1	`fixed-clock`
	on-chip	STM32L0/L1 Multi Speed Internal Clock1	`st,stm32l0-msi-clock`
	on-chip	STM32 LSE Clock1	`st,stm32-lse-clock`
	on-chip	STM32L0/L1 Main PLL1	`st,stm32l0-pll-clock`
Counter	on-chip	STM32 counters6	`st,stm32-counter`
DAC	on-chip	STM32 family DAC1	`st,stm32-dac`
DMA	on-chip	STM32 DMA controller (V2)1	`st,stm32-dma-v2`
Flash controller	on-chip	STM32 Family flash controller1	`st,stm32-flash-controller`
GPIO & Headers	on-chip	STM32 GPIO Controller6	`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	ARMv6-M NVIC (Nested Vectored Interrupt Controller) controller1	`arm,v6m-nvic`
Interrupt controller	on-chip	STM32 External Interrupt Controller1	`st,stm32-exti`
LED	on-board	Group of GPIO-controlled LEDs1	`gpio-leds`
LoRa	on-board	Semtech SX1276 LoRa Modem1	`semtech,sx1276`
Memory controller	on-chip	STM32 Battery Backed RAM1	`st,stm32-bbram`
MTD	on-chip	STM32L0 flash memory1	`st,stm32l0-nv-flash`
	on-board	Fixed partitions of a flash (or other non-volatile storage) memory1	`fixed-partitions`
	on-chip	STM32 on-chip EEPROM1	`st,stm32-eeprom`
PHY	on-chip	This binding is to be used by all the usb transceivers which are built-in with USB IP1	`usb-nop-xceiv`
Pin control	on-chip	STM32 Pin controller1	`st,stm32-pinctrl`
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`
Sensors	on-chip	STM32 VREF+1	`st,stm32-vref`
Serial controller	on-chip	STM32 USART2 2	`st,stm32-usart`
Serial controller	on-chip	STM32 LPUART1	`st,stm32-lpuart`
SMbus	on-chip	STM32 SMBus controller3	`st,stm32-smbus`
SPI	on-chip	STM32 SPI controller2	`st,stm32-spi`
SRAM	on-chip	Generic on-chip SRAM description1	`mmio-sram`
Timer	on-chip	ARMv6-M System Tick1	`arm,armv6m-systick`
	on-chip	STM32 timers6	`st,stm32-timers`
	on-chip	STM32 low-power timer (LPTIM)1	`st,stm32-lptim`
USB	on-chip	STM32 USB controller1	`st,stm32-usb`
Watchdog	on-chip	STM32 watchdog1	`st,stm32-watchdog`
Watchdog	on-chip	STM32 system window watchdog1	`st,stm32-window-watchdog`

Connections and IOs

B-L072Z-LRWAN1 Discovery kit has GPIO controllers. These controllers are responsible for pin muxing, input/output, pull-up, etc.

Available pins:

For detailed information about available pins please refer to B-L072Z-LRWAN1 website.

Default Zephyr Peripheral Mapping:

UART_1_TX/RX: PA9/PA10 (Arduino Serial)
UART_2_TX/RX: PA2/PA3 (ST-Link Virtual COM Port)
SPI1 NSS/SCK/MISO/MOSI: PA15/PB3/PA6/PA7 (Semtech SX1276 LoRa* Transceiver)
SPI2 NSS/SCK/MISO/MOSI: PB12/PB13/PB14/PB15 (Arduino SPI)
I2C1 SCL/SDA : PB8/PB9 (Arduino I2C)

System Clock

B-L072Z-LRWAN1 Discovery board System Clock is at 32MHz.

Serial Port

B-L072Z-LRWAN1 Discovery board has 2 U(S)ARTs. The Zephyr console output is assigned to UART2. Default settings are 115200 8N1.

USB device

B-L072Z-LRWAN1 Discovery board has 1 USB device controller. However, the USB data lines are not connected to the MCU by default. To connect the USB data lines to the MCU, short solder bridges SB15 and SB16.

Programming and Debugging

B-L072Z-LRWAN1 Discovery board includes an ST-LINK/V2-1 embedded debug tool interface.

Applications for the b_l072z_lrwan1 board configuration can be built and flashed in the usual way (see Building an Application and Run an Application for more details).

Flashing

The board is configured to be flashed using west STM32CubeProgrammer runner, so its installation is required.

Alternatively, OpenOCD or JLink can also be used to flash the board using the --runner (or -r) option:

$ west flash --runner openocd
$ west flash --runner jlink

Flashing an application to B-L072Z-LRWAN1 Discovery board

Here is an example for the Hello World application.

Connect the B-L072Z-LRWAN1 Discovery board to a STLinkV2 to your host computer using the USB port, then run a serial host program to connect with your board. For example:

$ minicom -D /dev/ttyACM0

Then build and flash the application:

# From the root of the zephyr repository
west build -b b_l072z_lrwan1 samples/hello_world
west flash

You should see the following message on the console:

$ Hello World! arm

Debugging

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

# From the root of the zephyr repository
west build -b b_l072z_lrwan1 samples/hello_world
west debug