What is it?

This is a small and low-power STM32WL based LoRa®/LoRaWAN® dev-board with all the necessary components for rapid prototyping.

Specs (SoC):

• STM32WLE5JC Wireless SoC
• ARM Cortex M4 ultra-low-power MCU
• Integrated SX1262 RF transciever
• Frequency range: 150 MHz to 960 MHz.
• Modulation: LoRa®, (G)FSK, (G)MSK and BPSK
• Transmitter power: programmable up to +22 dBm

MAMWLE-01 module specs:

• Multiprotocol LPWAN 32-Bit Arm Cortex-M4 MCU
• LoRa, (G)FSK, (G)MSK, BPSK
• 128KBFlash, 64KB SRAM
• ADC, DAC, DMA, comparators, timers, independent watchdog timer
• Ultra-low-power features
• 868Mhz to 915Mhz frequency range
• Interfaces: 37 GPIOs, 2x SPI, 3x I2C, 2x USART, 1x LPUART, 1x JTAG, 1x SWDIO
• Clock: 32MHz TCXO, 32.768KHz XTAL
• Tx power:
• Low power path: Up to +14dBm
• High power path: Up to +22dBm Dimensions: 16.5mm x 15.5mm x 2.0mm LGA-66 package

MAMWLE-XX module's average power consumption in different modes (@3.0 VDD):

• Run Mode (48 MHz): 7.4 mA
• Sleep Mode (48 MHz): 2.1 mA
• STOP 0: 400 µA
• STOP 1: 4.20 µA
• STOP 2: 0.885 µA
• Standby Mode: 255 µA
• Shutdown Mode: 31 nA

Penguino's power consumption (STM32WL in STOP2 mode w/ RTC enabled, @4.3 VBAT input):

• PWR LED ON: ~590 µA
• PWR LED OFF: ~60 µA (JP2 cut, LED disabled, USB-TTL converter ON)
• PWR LED OFF: ~7.9 µA (JP7 cut, USB-TTL converter disabled)*

*by cutting the JP3 and JP4 (VBAT monitoring voltage divider) power consumption can further be reduced down to ~6 µA.

Why did you make it?

I needed a breakout board compatible with other Penguino boards so I can evaluate this nifty little module. Check out Move-X's official GitHub repo for more awesome examples (Arduino, AT command example, etc.)

What makes it special?

Unlike the official NUCLEO-WL55JC dev-board, this one is purpose designed to be low-power. Additionally, unlike other STM32WL radio modules this one breaks out all available GPIOs, while providing the flexibility of choosing either the +14dBm or the +22dBm output paths (HP and LP paths). This allows the user to carefully choose the max output power and save on the battery life.

Feather style also provides better usability thanks to the wide selection of Feather compatible add-ons and expansion boards. Be sure to checkout the awesome-feather repo.

Programming

Device comes with a RGB toggle example preloaded, but there's also a simple LoRaWAN end node example in my repo. You'd need a ST-Link v2/v3 or any STM32 compatible SWD/JTAG programmer to flash the device.

Notes

Since this was a low volume prototyping run I very limited number of boards available. Once the first batch clears out, I'll set out to produce some more. By default RF path is routed to the SMA connector and the board doesn't come with an antenna. You may include one in the options above.