LoRa®-based Solutions for Low Power

One of Renesas’ solutions comprises a low power RL78 microcontroller (RL78/G23, RL78/G22, RL78/G14) and a LoRa® transceiver (Semtech SX1261/SX1262) for low power operation. This solution contributes to the realization of IoT sensor end-devices with long battery life.

RL78 LoRa®-based Solutions System Block

LoRaWAN® Average Current (Estimation): LoRaWAN® Class A Operation - TX + RX (ACK)

RL78 LoRaWAN® Average Current

Low power consumption of LoRaWAN® stack

  • LoRaWAN® stack shifts RF part to the most suitable low consumption mode automatically according to the internal operating state.
  • MCU part can be shifted to a low consumption mode during frame sending and receiving.
  • Low power timer function optimized for intermittent operation is supported. This can also be used from an application.

Development Environment for Easy Development and Evaluation

The software development environment consists of the RL78/G23-64p Fast Prototyping Board, RL78/G23-128p Fast Prototyping Board, RL78/G22 Fast Prototyping Board or RL78/G14 Fast Prototyping Board and the Semtech SX1261/SX1262. The use of wireless receivers and transmitters is restricted by international standards and domestic regulations. Wireless receivers and transmitters must therefore be used in accordance with the applicable laws and regulations of the country in which they are being used.

RL78/G23-64p, RL78/G23-128p, RL78/G14, RL78/G22 Fast Prototyping Board

Software for Ease of Design

Renesas offers software for controlling a LoRa® transceiver (Semtech SX1261/SX1262) using a low power RL78 microcontroller (RL78/G23, RL78/G22, RL78/G14). For applications that require interoperability, there is the LoRaWAN® protocol stack based on the LoRaWAN® specification which implements LoRaWAN® protocol (Class A, Class B* and Class C) specified in the specification version 1.0.4/1.0.3/1.0.2. Control is performed using AT commands. (*Class B conforms to version 1.0.4/1.0.3) For applications for which interoperability is not necessary, there are the LoRa®-based network software (private LoRa®-based network sample) and the radio driver for LoRa® for custom protocol implementation.

RL78 LoRa software

Supporting of Firmware Update over LoRaWAN®

FUOTA (Firmware Updates Over The Air) provides a function to remotely update a firmware over wireless communication. This function is a key feature for IoT applications deployed widely in the field and that require long term operation. The LoRa Alliance® standardized the FUOTA process utilizing the application layer protocols on top of the LoRaWAN® protocol, such as Clock Synchronization Message Package, Remote Multicast Setup Package and Fragmented Data Block Transport Package. These protocols can deliver a firmware image to multiple devices at the time specified by an application server.

Firmware Update over LoRaWAN®

Private LoRa®-based Network Sample

The private LoRa®-based network sample provides a small network environment using LoRa®-based protocol. It allows direct and indirect transmissions between devices, as well as bidirectional communication. In addition, AT commands can be used to control intermittent operation and key exchange necessary for security, making it easy to construct a network environment. Furthermore, the communication interval can be flexibly changed, which is useful for balancing the amount of data communication and power consumption.

Private LoRa®-based Network Sample

LoRaWAN® and Private LoRa®-based Network Combination Sample

For LoRaWAN® and Private LoRa®-based network combination sample, LoRaWAN® and private LoRa®-based network can be switched dynamically (time-division operation), which is suitable for wide-area / large-scale network communication and small / ad-hoc network communication, respectively. The communication can be resumed immediately after the network switch by retaining the parameters required for LoRaWAN® and private LoRa®-based network. In addition, this sample supports the low power function utilizing intermittent operation, the frame encryption, and the frame integrity check functions.

For example, in the case of an automatic meter reading application, LoRaWAN® can be used as the main network to collect the meter data automatically and the private LoRa®-based network can be used as the sub network for an operator to get the data directly from a meter when it is in a bad wireless environment. The private LoRa®-based network can be also used to set the parameters required for the applications and the LoRaWAN® communication when a meter is installed, or to get the statuses of a meter interactively when abnormal behavior or malfunction of the meter is detected.

LoRaWAN® and Private LoRa®-based Network Combination Sample

Wireless Communication Tools for Ease of Evaluation

Renesas offers tools that make evaluating characteristics easy. Renesas LPWA Studio can perform continuous CW/Modulation transmission, PER (Packet Error Rate) / BER (Bit Error Rate) measurement, and RSSI measurement. It also has a sniffer function that captures LoRa®/GFSK modulation frames over the air and displays analysis results, as well as a function that transmits temperature/humidity sensor information of HS3001 connected to the transmitting node and visualizes it at the receiving node. Renesas also offers a tool that estimates power consumption.

Renesas LPWA Studio

Example of Application

  • Introduces you how to visualize sensor data transmitted by the RL78 Sensor Node to the Cloud (AWS/Azure) via LoRaWAN® networks. Refer to LoRaWAN® Sensor Demo.

    Visualize sensor data transmitted by the RL78 Sensor Node to the Cloud
    LoRaWAN® communication with Bluetooth® Low Energy communication and send sensor data to LoRaWAN® Gateway with LoRaWAN® communication.
  • Winning Combinations:
    LoRaWAN®-Based Gas Meter
    Smart Livestock Farming


DTDS Technology Pte Ltd

Product Description & Features

DTDS’s 622 Module is LoRaWAN® compliant with both Class A and Class C of the protocol specification and includes an embedded Renesas RL78/G13 microcontroller to provide leading low power consumption for use in smart utility, smart home, smart agriculture, smart lighting, and smart transportation applications. It is suitable for long range sensor-based interfaces with an external host MCU over AT commands and supports the 868MHz, 915MHz and 923MHz operation bands.

Key Features:

  • Best performance in operating voltage (VCC) range: 1.8 to 3.7V
  • Best performance in receiver sensitivity performance: -137dBm @ SF12 BW=125KHz
  • Lowest in transmission current: 122mA @ 22dBm
  • Low power consumption to enhance battery life (>10 years)
  • UFL connector for design flexibility
  • Evaluation board with industry standard PMOD interface and two antenna connector interfaces (SMA, UFL) for development purposes


DTDS Technology Pte Ltd Logo
DTDS board
DTDS 662

DTDS Details




Software Downloads

Type Title Date
Sample Code
Log in to Download ZIP 2.97 MB
Application: Communications Infrastructure, Consumer Electronics, Industrial
Compiler: CC-RL Function: Software Package IDE: CS+ for CC, e2 studio
Sample Code
Log in to Download ZIP 16.54 MB
Application: Appliances, Building Automation, Industrial Automation, Metering, Wireless Infrastructure
Compiler: CC-RL Function: Software Package IDE: CS+ for CC, e2 studio
Sample Code Log in to Download ZIP 2.97 MB Compiler: CC-RL IDE: CS+, e2 studio
3 items


RL78 LoRa®-based Solution

This video introduces RL78 LoRa®-based Solution.
It realizes a true low-power wireless IoT system by combination of the world's top-class low power RL78 microcontroller and LoRaWAN®