RAKwireless has introduced the RAK4270 LoRa Module that is based on the STM32L071 MCU and SX1262 LoRa chip. It supports the LoRaWAN 1.0.2 specification and can also work on Class A and Class C mode making it compatible to different LoRaWAN network servers. The module works well on both ABP and OTAA activation methods. It also supports eight spreading factors from SF5 to SF12 with a configurable signal bandwidth from 7.8 kHz to 500 kHz.
LoRa modules usually consist of two main parts: the microcontroller and the LoRa RF radio. The RAK4270 uses the STM32L071 as the Microcontroller and the latest LoRa radio chip SX1262. Other internal components are passive components that optimize RF performance and power consumption.
LoRa radio chips like the SX1262 use a unique Chirp Spread Spectrum (CSS) modulation which is a proprietary spread spectrum technique patented by Semtech Corporation. SX1262 is the latest sub-Ghz LoRa chip offered by Semtech. It has new features from its predecessor RF chips, is a little bit smaller in size, offers faster data rate, has the option to transmit on higher transmitting power and with lower power requirement on receiving mode. All these new features are inside the RAK4270 module.
There are applications where LoRaWAN is really not needed, and a LoRa P2P (Point to Point) communication is more applicable. RAK4270 is capable of that feature with configurable spreading factor, frequency, bandwidth, coding rate, preamble and even the transmitting power. With two RAK4270, a perfect long range communication between two devices can easily be set up. It can also switch functionality to either TX or RX since the LoRa module is a transceiver.
In terms of electrical characteristics, the module can operate on a very wide voltage range from 2.0 V to 3.6 V. This kind of voltage range is ideal for IoT battery powered applications since users can squeeze up to what is left on the battery without having to worry about any under-voltage shutdown. Another great feature is its low power requirement. It will only consume 2.19 uA in sleep mode (down to 1.74uA at 2.0V) operating at EU868 frequency.
RAK4270 is available as a stamp module that measures 15 x 15.5 x 2.5 mm making it ideal for space constrained projects. With the IPEX connector on the module, there is flexibility on the type of antenna depending on the user’s preference. Its whole circuit is also metal shielded making it robust against RF interference.
Apart from the stamp module form factor, there is also the RAK4270 Breakout Board. This is ideal for quick IoT device prototyping and proof of concept demo units. Users can use its RP-SMA connector for making a direct antenna connection.
The RAK4270 comes with a default UART AT Commands set. LoRaWAN and LoRa P2P configurations for the module can be done via these standard commands. One bonus feature on this command set is the ability to control the specific IO pins of RAK4270 using certain commands. It has GPIO and ADC pins which can be used on the IoT application of the user.
Another option for developing the software for RAK4270 is via the RAKwireless Unified Interface which is also called RUI. It is an API based firmware driver that abstracts the complexity of the hardware layer of the module. Through the RUI API, users can control all the functionalities of the RAK4270 module without the need to deal with the complexity of low-level hardware protocols such as UART, I2C, etc. RUI is also compatible to other WisNode, WisDuo and WisTrio modules.
RAK4270 modules are sold globally because it was tested to the meet the requirements of CE and FCC. It also passed the ROHS standard. In addition to that, RAK4270 and other WisDuo, WisTrio and WisNode products have unique DEVEUI which RAKwireless secured from IEEE Registration Authority.
Click here to learn more about the RAK4270 LoRa module.
Click here to view LoRa frequency bands.
