$6 RAK3172 WisDuo LoRaWAN module features STMicro STM32WL LoRa SoC

RAK3172 WisDuo is a LoRaWAN module smaller than most coins with 15.5×15 mm dimensions made possible thanks to STMicro STM32WL Cortex-M4 LoRa SoC, which we previously found in Seeed Studio’s $10 LoRa-E5 module and corresponding development boards.

But while Seeed Studio relies on STM32WLE5JC SoC with 256KB flash and 64KB RAM in a 73-pin UFBGA package, RAKwireless RAK3172 Wisduo is powered by STM32WLE5CC with the same amount of memory or storage, but in a 48-pin UFQFPN package, and an even lower price at just $5.99 in single units.

RAK3172 Wisduo specifications:

SoC – STMicro STM32WLE5CC55 Arm CortexM4 MCU @ 48 MHz with 256 KB flash memory with ECC, 64 KB RAM, and a sub-GHz radio based on Semtech SX126x
LoRaWAN 1.0.3 specification compliant
Supported bands – EU433, CN470, IN865, EU868, AU915, US915, KR920, RU864, and AS923
LoRaWAN Activation by OTAA/ABP
LoRa Point to Point (P2P) communication
Range – Greater than 15 km with optimized antenna
Host interface – UART with AT Command Set via UART interface
Other I/Os – SPI, I2C, ADC, GPIO
Supply Voltage – 2.0 V ~ 3.6 V
Dimensions – 15.5 x 15 mm
Power Consumption – 1.69 μA in sleep mode
Temperature Range – -40°C to 85°C

The module can connect to various LoRaWAN server platforms like TheThingsNetwork (TTN), Chirpstack, Actility, etc…, and also supports LoRa Point to Point (P2P) communication mode so a gateway may not even be needed.

You’ll find documentation and firmware files for the module on RAKwireless documentation website. I also noticed ARMbed repository on Github with the code to run Arm mbed OS on the two STM32WL modules we’ve discussed in this post.

RAK3172 Wisduo module can be purchased on RAK’s one shop for $5.99 plus shipping. There’s also the RAK3272S breakout board which will allow you to more easily access the I/O of the module sold for $15.

I remember when we started to write about LPWAN technology several years ago, the long-term goal was to get $2 LPWAN modules, and we’re not there yet albeit close with some 868/915MHz modules going for under $4, but considering WiFi IoT modules can be had for that price, I don’t see why eventually LoRa, Sigfox, and/or other LPWAN modules could not eventually become just as cheap.

Jean-Luc Aufranc (CNXSoft)

Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.