ROHM Co., Ltd.

Introducing the MK71050-03 Bluetooth® SMART Compatible Wireless Communication Module

Blog post   •   Feb 25, 2016 14:00 GMT

The advent of the Bluetooth Smart standard for connecting devices such as wearable tech with smartphones, notebook PCs, and tablets is expected to result in increased adoption in a variety of locations.

However, developing wireless communication devices often requires a high level of expertise and experience in high frequency (antenna) design and circuit optimization. This in turn has brought about a demand for wireless modules that can be easily used - even by those without previous experience or knowledge about configuring wireless systems and/or acquiring the necessary certifications.

In response, LAPIS Semiconductor has developed a wireless communication module compatible with Bluetooth® Smart. Below we give an overview of the MK71050-03 wireless module along with the optional evaluation kit and development tools.



The MK71050-03 module integrates LAPIS Semiconductor’s market-proven ML7105 wireless communication IC with a 16kB EEPROM, 26MHz crystal oscillator for the master clock, and pattern antenna (Figure 1) – all into a compact form factor.

In addition, various adjustments for wireless communication are no longer needed, and wireless certifications in major regions (Japan, the US, and Europe) – along with Bluetooth SIG – have already been obtained, enabling immediate use even by customers with little to no wireless experience. Also, the inclusion of our wireless communication IC negates the black box concept, making it possible to provide rapid and comprehensive development support.

The block diagram of MK71050-03 is shown in Figure 2, with key specifications listed in Table 1.

Connection with the host microcontroller is made via SPI, while commands and data format unique to LAPIS Semiconductor are implemented using a combination of three dedicated terminals – an IRQ pin used to send interrupt notification signals from the ML7105 to the host MCU, a WAKEUP pin for detecting the response signal from the host MCU, and an RF Active pin for receiving signals indicating the status of wireless communication.

The storage area of the internal 16kB EEPROM consists of a 128-Byte configuration data region for storing relevant parameters (i.e. transmission output settings, Bluetooth® device address) that determine the basic operation of the ML7105 wireless communication IC, and an application region usable by the host MCU (approx. 15kB).

The built-in pattern antenna, developed in collaboration with French company Insight SiP, is optimized for the ML7105 and ensures excellent propagation characteristics.

Regarding wireless certification, Construction Design certification in Japan (Certification No. 006-000238) and FCC certification in the United States (FCC ID: 2ACIJ71050-3) have already been acquired. And in Europe compliance with wireless testing has been achieved in accordance with the R&TTE Directive (Testing Standard EN300 328 V1.8.1). Plus, due to the interoperability of Bluetooth® Smart devices the module has received Bluetooth® SIG certification (End Product, QDID: 66491).

Figure 1. MK71050-03 Wireless Module         

Figure 2. MK71050-03 Block Diagram

Table 1. MK71050-03 Specifications         


Evaluation Kit Overview

To facilitate evaluation of the MK71050-03 the MK71050-03USB-EK USB dongle-type evaluation kit was developed that utilizing LAPIS Semiconductor’s ML610Q482 8bit MCU as the host microcontroller (Figure 3).

In addition, BLE Tool, a smartphone app that makes it possible to immediately confirm communication and conduct evaluation by controlling various functions through Bluetooth® Smart, is available free of charge from Google Play.


Figure 3. MK71050-03USB-EK Evaluation Kit



The MK71050-03 USB-EK evaluation kit enables control of various settings and communication operations by AT command and supports the following functions.

-Peripheral Mode Connection Control (Advertise/Pairing/Connection/Disconnection)

-Central Mode Connection Control (Scanning/Pairing/Connection/Disconnection)

-Pairing Function (Just Works/Passkey entry): Pair with up to 5 terminals

-Settings for terminal-specific information (BD Address, etc.)

-Settings for various parameters (Advertise/Scanning/Connection and iBeacon Parameter Settings)

Also, because the MK71050-03USB-EK can function as both a Central (Master) with Bluetooth® Smart connection and a Peripheral (Slave), it can be connected to a smartphone (Central) with BLE Tool installed. Or, alternatively, two MK71050-03USB-EKs can be configured to communicate with each other (in a Central-Peripheral configuration). The various parameter settings and communication controls for the MK71050-03USB-EK are carried out either via the terminal software or LAPIS Semiconductor’s evaluation kit utility program (Figure 4). When using the evaluation kit utility program, read/write operation, Central/Peripheral mode connection control, and serial data transmission (after connection is established) can easily be implemented via GUI.

Figure 4. MK71050-03 Evaluation Kit Utility Program



With BLE Tool (Figure 5), scanning Bluetooth® Smartdevice, connection, and data transmission are performed using a simple user interface. The following BLE standard and vendor-specific profiles and services are supported.

Supported BLE Profiles and Services

- HRP: Heart Rate Profile

- HTP: Health Thermometer Profile

- BLP: Blood Pressure Profile

- GLP: Glucose Profile

- BAS: Battery Service

- DIS: Device Information Service

- VSSPP: Vendor Specific Serial Port Profile

(Please note that BLE Tool is compatible with smartphones and tablets equipped with Bluetooth® Smart running Android 4.3 or later)

Figure 5. BLE Tool Screen Images     


Future Prospects

Going forward LAPIS Semiconductor will continue to develop wireless communication modules and LSIs that make it easy for almost anyone to easily configure a wireless communication environment for IoT applications and devices.

And LAPIS Semiconductor will continue to leverage the strengths of the ROHM Group to expand its solutions business by combining wireless, MCU, sensor, and power supply technologies.