RAK3272S Breakout Board Datasheet
Overview
Description
RAK3272S Breakout Board is specifically designed to allow easy access to the pins on the board to simplify development and testing. The breakout board footprint allows the RAK3172 stamp module pins to be transferred to 2.54 mm headers.
The board itself has the RAK3172 at its core, integrating a STM32WLE5CC chip. It has an ultra-low power consumption of 1.69 uA in sleep mode.
This module complies with Class A, B, and C of LoRaWAN 1.0.3 specifications. It also supports LoRa Point-to-Point (P2P) communication mode, which helps you implement your own customized LoRa network quickly.
Features
- Based on RAK3172
- Custom firmware using Arduino via RUI3 API
- I/O ports: UART/I2C/GPIO/SPI
- Serial Wire Debug (SWD) interface
- Module size: 25.4 mm x 32.3 mm
- Ultra-low-power consumption of 1.69 uA in sleep mode
- Supply Voltage: 2.0 V ~ 3.6 V
- Temperature Range: -20° C ~ 85° C
Specifications
Overview
The top view of the RAK3272S Breakout Board is shown in Figure 1.
Hardware
The hardware specification is categorized into five (5) parts. It discusses the interfacing, pinouts, and their corresponding functions and diagrams. It also covers the electrical and mechanical parameters of the board, including the tabular data of the functionalities and standard values.
Interface
SWD Programming Interface
When programming via a ST-Link tool, it is required to have the following four pins connected to your ST-Link tool:
- 3V3
- SWDIO
- SWCLK
- GND
UART Interface
This board has two UART interfaces:
- UART1 (can allow AT commands if configured via RUI3 Serial Port Mode)
- UART2/LPUART1 (allows AT Commands and FW Update)
I2C and SPI Interface
Only one I2C and SPI interface of RAK3272S:
- I2C2
- SPI1
RF Interface
J3 is soldered to the antenna connector. Depending on your choice, it comes with either SMA or IPEX style connector. Make sure to select the one you need when ordering.
Pin Definition
The tables below show the pin definition of the RAK3272S Breakout Board:
J5 Pin Definitions
| Pin No. | Name | Description | STM32WLE5CC Pin |
|---|---|---|---|
| 1 | SPI_MOSI | GPIO and SPI (MOSI) | PA7 |
| 2 | SPI_MISO | GPIO and SPI (MISO) | PA6 |
| 3 | SPI_CLK | GPIO and SPI (CLK) | PA5 |
| 4 | SPI_CS | GPIO and SPI (NSS) | PA4 |
| 5 | UART1_RX | UART1 Interface | PB7 |
| 6 | UART1_TX | UART1 Interface | PB6 |
| 7 | GND | Ground | - |
| 8 | BOOT0 | Boot0 mode enable pin - high active | - |
| 9 | 3V3 | Power Supply | - |
J4 Pin Definitions
| Pin No. | Name | Description | STM32WLE5CC Pin |
|---|---|---|---|
| 1 | I2C2_SDA | I2C2 interface | PA11 |
| 2 | I2C2_SCL | I2C2 interface | PA12 |
| 3 | RST | MCU Reset | - |
| 4 | GND | Ground | - |
| 5 | SWDIO | SWD debug pin (SWDIO) | PA13 |
| 6 | SWCLK | SWD debug pin (SWCLK) | PA14 |
| 7 | UART2_TX | UART2/LPUART1 Interface (AT Commands and FW Update) | PA2 |
| 8 | UART2_RX | UART2/LPUART1 Interface (AT Commands and FW Update) | PA3 |
| 9 | 3V3 | *Power Supply (check warning) | - |
-
The J4 pin definition table is applicable to RAK3272S VerC. If you have RAK3272S VerB, pin 9 is not 3V3 but connected to PA8.
-
A dedicated internal SPI interface called SUBGHZSPI is used to communicate with the RF subsystem of the STM32WLE5CC.
RF Characteristics
The RAK3272S module supports the LoRaWAN bands shown in the table below. When buying a RAK3272S module, pay attention to specify the correct core module RAK3372PL or RAK3372 for your region. The suffix L is for low-frequency regions, but no suffix (RAK3172P) means for high-frequency regions.
| Module | Core Module | Region | Frequency |
|---|---|---|---|
| RAK3272SL | RAK3172PL | Europe | EU433 |
| RAK3172PL | China | CN470 | |
| RAK3272S | RAK3172P | Europe | EU868 |
| RAK3172P | North America | US915 | |
| RAK3172P | Australia | AU915 | |
| RAK3172P | Korea | KR920 | |
| RAK3172P | Asia | AS923-1/2/3/4 | |
| RAK3272P | India | IN865 | |
| RAK3272P | Russia | RU864 |
Electrical Characteristics
Power Consumption
| Feature | Condition | Minimum | Typical | Maximum | Unit |
|---|---|---|---|---|---|
| Operating Current | TX Mode | 87 @ 20 dBm, 8680 MHz | - | - | mA |
| RX Mode | 5.22 | - | - | mA | |
| Sleep Current | EU868 | - | 1.69 | - | uA |
| CN470 | - | 1.69 | - | uA |
Operating Voltage
| Feature | Minimum | Typical | Maximum | Unit |
|---|---|---|---|---|
| VCC | 2.0 | 3.3 | 3.6 | V |
Schematic Diagram
Mechanical Characteristics
Figure 4 show RAK3272S board dimensions.
Software
Download the latest firmware of the RAK3272S Breakout Board provided below. RAK3272SL and RAK3272S use the same firmware, and it will automatically detect the variant of the module being used.
The bin file contains the application code only and you need the RAK DFU Tool to upload this file to the module.
The hex file contains both the bootloader and the application code. You need to use STM32CubeProgrammer to upload this.
Uploading the .hex file via STM32CubeProgrammer will erase all configured data on the device.
RAK3272S uses UART2 serial pins to upload the latest firmware.
RAK3272S should automatically go to BOOT mode when the firmware is uploaded via RAK DFU Tool or WisToolBox.
If BOOT mode is not initiated, you can manually send AT+BOOT command to start bootloader mode.
Firmware / OS
| Model | Version | Source |
|---|---|---|
| RAK3272S(.bin) | RUI3 (default baudrate = 115200) | Download |
| RAK3272S(.hex) | RUI3 (default baudrate = 115200) | Download |
| RAK3272S | DEPRECATED V1.0.4 (default baudrate = 9600) | Download |
There are RAK3172 devices loaded with old firmware versions which are not based on RUI3 (RAKwireless Unified Interface V3). These devices have v1.0.4 and below.
If the host microcontroller code is based on this old firmware, refer to RAK3172 AT Command migration guide, which explains in detail the few differences between the two AT commands set.
