With the expansion of the Internet of Things (IoT) market, including infrastructure, agriculture and automobiles, many services, applications and devices for realizing IoT have emerged, and various companies have been advancing businesses targeted at the market.

The concept of IoT will probably be put into form as follows: huge amounts of data are collected from the real space and sent to a cloud computer through the Internet. The collected data is processed in the cloud computer, where systems in the real world are controlled on the basis of the results of the processed data. As a result, systems in the real world can be optimized. However, in order to realize IoT, a significantly wide range of technologies and knowledge are required, and therefore, it is not possible for a single company to cover all the technologies needed.

On the basis of this concept, ROHM has been focusing efforts on the mechanism to upload data from the real space to the cyber space. Sensor devices and Wireless communication devices, which are indispensable for collecting data from the real space, are one of technologies at the center of the company’s efforts.

ROHM’s Sensor Devices for IoT

ROHM’s sensor devices consist of abundant sensor elements with micro electro mechanical systems (MEMS) technology at the core and optimum control circuits (application specific integrated circuits (ASICs)) that give the elements full play. ROHM’s Sensor lineup includes motion sensors (MEMS), such as accelerometers, angular velocity, geomagnetic field sensor, and also field sensors, such as barometric-pressure sensors, RGB-color sensors, ambient light/proximity sensors, temperature sensors, and UV sensors (Fig. 1).

ROHM offers these sensor devices for various applications centering on mobile devices, IoT. The company has also been endeavoring to expand new lineups, advancing the development of pulse wave sensors (Heart Rate) and soil sensors to meet the needs of the agricultural and medical/healthcare fields.

Fig. 1: ROHM’s sensor lineup

ROHM’s Sensor Evaluation Kits

At the same time, needs not only for devices but also for tools that enable easy evaluation of the devices have been increasing. Responding to these requirements, ROHM has recently released two sensor evaluation kits in order to contribute to the proliferation of IoT.

Table 1: Sensors incorporated in SensorShield-EVK-001
Fig. 2: Individual sensors mounting of SensorShield-EVK-001

Arduino-compatible SensorShield-EVK-001

The SensorShield-EVK-001 kit comprises ROHM Group’s eight sensor products mounted on the substrate and a board for connection to open platforms (Table 1). It enables users in the electronic handicraft field to easily measure acceleration and other information by connecting the kit to Arduino Uno or mbed that are widely used around the world and incorporating software. Through easy evaluation and easy introduction of sensor devices, it significantly reduces the development manhours of IoT equipment (Fig. 2).

Meanwhile, ROHM was made with the preparation to enable customers to purchase the evaluation kit from major Internet trading firms around the world the last year. The company prepare documents and software that are necessary for realizing sensing. The company is providing the information on its homepage.

SensorMedal-EVK-001 evaluation kit

SensorMedal-EVK-001 (Fig. 4) is a substrate on which four sensors essential for motion sensing, a Bluetooth Smart module, which has obtained a certification conforming to the Radio Law, and a 16-bit low-power microcontroller unit (MCU), and other components are mounted. By controlling various sensors and the Bluetooth Smart module using the low-power MCU, it enables users to easily construct energy-saving sensor environments. Sensor evaluation that simulates practical use significantly reduces development manhour of wearable devices and other IoT devices (Fig. 5).

Fig. 4: Schematic of SensorMedal-EVK-001
Fig. 5: Evaluation using Android app

Model No. SensorShield-EVK-001 SensorMedal-EVK-001
Applications Electronic handcraft, prototype development of a wide range of devices Prototype development of low-power systems, such as wearable devices and IoT devices
Features • Operation with open platforms, such as Arduino

• Expansion of functions is easy

• Wide range of applications

• Large size (62mm x 87mm)

• Linkage with smartphone, tablet is possible.

• Equipped with a microcontroller, it operates on its own.

• Equipped with a radio function

• Specific applications

• Compact size (φ33mm)

• Low power consumption for operation

Sensors incorporated Total of eight sensors: accelerometer, barometric pressure, geomagnetic field, ambient light/proximity, color, magneticfield, temperature, and UV sensors. Total of four sensors: accelerometer, barometric pressure, geomagnetic field, and angular velocity (gyro) sensors.

Table 2: Comparison of ROHM’s sensor evaluation kits

ROHM’s Wireless Communication Devices (Short-Range) for IoT/ Smart meters

Systems that connect different devices require a way for detecting and consolidating sensor data. A network is necessary to connect the sensors to a server to transmit and store this data for analysis. But configuring a wired network entails connecting wires to multiple sensors, which can be very time-consuming. This is why short-range wireless communication is attracting increased attention in the IoT market.

The ROHM Group offers a range of products that support a variety of short-range wireless communication protocols (Fig. 6), allowing users to select the ideal solution based on application requirements. However, ROHM also understands the need for connectivity, and takes the following into account when developing products.

1.Communication protocols must be internationally standardized

2.Wireless protocols must be optimized for client applications

3.The modules should be Radio Act certification (Japan) and/or compliant with other Global/universal protocols in order to ensure compatibility while reducing design load

Fig.6: ROHM Group Short-Range Wireless Communication Device Lineup

The ROHM Group offers wireless communication ICs and modules that make it possible to quickly and accurately meet customer needs. For customers familiar with high-frequency designs, ROHM provides standalone wireless communication ICs. And for clients who wish to reduce design load (or without no wireless network experience), ROHM-modules that featuring built-in software and antenna (Radio Act-certified), significantly reduces design load. Depending on the application, ROHM delivers optimized solutions leveraging the latest IoT technologies tailored to customer demands.

Regarding wireless communication frequency, ROHM offers a lineup compatible with the 920MHz band (Sub-GHz), which was released under the 2012 revision of the Japan Radio Act. The Sub-GHz band delivers the following benefits that are expected to increase applicability and adoption in a range of markets and applications.

  1. Wider coverage area than 2.4GHz band due to superior radio diffraction and bending characteristics
  2. Less susceptible to interference from 2.4GHz devices, minimizing the risk of cross-talk
  3. Less susceptible to interference from noise sources in the 2.4GHz band, such as factory equipment and microwaves ovens.

Next ROHM introduces a few applications of Sub-GHz communication. Wireless networking Technology using IoT for home automation is going to change the way how devices are being used.

Wi-SUN Communication Used in Smart Meters

Wi-SUN (Wireless Smart Utility Network) is a low-power wireless protocol certified for smart meters (next-generation Energy-meters for AMI) that enables bi-directional communication at distances of up to nearly 1km. IEEE 802.15.4g and IEEE802.15.4e specify the physical and MAC layers, respectively. An additional protocol, Wi-SUN HAN (Home Area Network), was established to connect home electronics with smart meters and Home Energy Management Systems (HEMS). Adoption in controller devices continues to progress due to an increase in smart meter installations following the Japan’s deregulation of power utilities in April 2016 (Fig. 7). This open communication standard is anticipated to improve convenience by allowing communication between different home electronics devices, which up to now was contingent on the manufacturer.

Fig. 7:HEMS using Wi-SUN communication Network

Multiple Wi-SUN standards for smart meters exist, including Route A for communication between the power/utility company and smart meters, Route B from smart meters to buildings, and HAN for within buildings. ROHM was among the first to develop wireless communication modules supporting the Wi-SUN standard, which continue to be adopted in smart meters and gateways. ROHM modules have been certified to be compliant with the Japanese Radio Act and as CTBU (Certified Test Bed Units) by the Wi-SUN Alliance, ensuring worry-free operation by enabling interoperability between certified devices. The BP35A1 is compatible with Wi-SUN Route B and already in mass production, and sample shipments have started for the next-generation BP35C0 and BP35C2, which are dual-compatible with Wi-SUN B Route/HAN. The BP35C0 is a surface-mount type that contributes to increased miniaturization while the BP35C2 is a USB dongle that provides Wi-SUN communication capability for existing gateways with a USB port without the need for hardware modifications (Fig. 8).

Fig 8: ROHM’s Lineup of Wi-SUN Communication Compatible Module Products


With the expansion of the IoT market in recent years, the diversification of applications and devices that realize IoT products have been advancing. Naturally, the demand and requirements for sensors, one of key devices that realize IoT, have been becoming increasingly greater.

Targeting the IoT market wherein applications continue to expand in the future, ROHM intends to continue to develop high-precision and diverse sensor devices and wireless communication devices and tools that promote innovations to contribute to the realization of safe and comfortable society.

About ROHM Semiconductor:

ROHM Co., Ltd. is an international semiconductor company headquartered in Kyoto- Japan, established in 1958. ROHM keeps providing highly-reliable electronic components, ICs, discrete, passive components, and modules, with wide-range of field such as consumer/IoT, automotive, and industrial equipment through our global network.

ROHM Semiconductor India Pvt. Ltd., headquartered in Bangalore, and has sales offices in Delhi, Pune, and Chennai, to cater to the ever-growing electronics market in India. ROHM-Bangalore also houses the Design Centre, with Application Engineering, LSI design, and Product strategy functions, to enhance local product support and design products.


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