Voice Recognition Enhances the HMI functions for Hardware to Support Real-Time Contactless Control

September 28, 2021

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Despite the efficiency of wireless design, the human-machine interface could be more advanced with the support of real-time and contactless features. Additionally, the current pandemic should make these contactless systems even more appropriate for operations and functioning. Voice recognition is one such attribute for building an ideal HMI system. 

What is HMI?

HMI is a human-machine interface that acts as a medium between the user and backend system. The objective of such an interface is to simplify the operation of a complexly designed system by embedding user-friendly functionalities. The compatibility of the interfacing medium with the control unit of the machine is crucial for designing these systems. Similarly, the interface should also support the integration of advanced user-friendly functionalities from the user’s perspective.

Credits: Author

Voice recognition is one of the advanced functionalities that makes the overall system simple for the user, although speech processing for recognition of the signals from the input audio could be difficult due to external noise and attenuation. But the current processing algorithms are competent enough to detect the voice signals distinctly. Additionally, the sensor and transducing technology have grown with respect to the hardware design and architecture, which further improves speech processing and voice recognition functionalities

Accommodating the voice recognition feature in HMI demands the real-time processing of speech signals. Hence the hardware should have the capacity of performing extensive computations without any significant delay. Additionally, the CPU core of the processor should operate at a higher frequency keeping up with the extensive processing. So, apart from the voice recognition and HMI functionalities, Renesas’ RX671 MCUs offer a competent performance for building such real-time contactless control systems.

Overview of Renesas RX671 Microcontrollers

Renesas is well known for its high-performing MCUs, especially the RX600 series which is perfect for building real-time applications with its high-processing performance based on the latest RX CPU core. Additionally, the microcontrollers support various peripheral functions that enable device control and network control with a single chip. Hence allowing more small devices developed with lesser parts needed.

Credits: Renesas

The processors feature an RXv3 CPU core working at a frequency of 120 MHz and it integrates flash memory that offers quicker read access at a clock speed of 60 MHz. Thus the deployed applications with this hardware can support real-time functionalities. Apart from its efficient real-time performance with a CoreMark score of 707, the RX671 MCUs are also power efficient with a score of 48.8 CoreMark/mA.

RX671 series offers a dynamic range of packages with respect to dimensions and memory specifications. Designing an end-to-end application becomes easier due to flexibility in accommodating the component in the target system. The dimensions of the most compact MCU of the series are 4.5mm x 4.5mm with a 64-pin configuration equipped with 2MB flash memory and 384KB SRAM. 

Architectural Block Diagram of Renesas RX671 Series

The internal peripheral bus of the architecture is connected to the capacitive touch sensing unit (CTSU) and serial sound interface, these blocks bring out the HMI functionalities of the RX671 series. Further, the touch sensing units can be interfaced with the proximity switches for enabling contactless control of the target system. The serial sound interface (SSIE) supports the voice recognition functionality by harnessing the input speech signals. 

Credits: Datasheet

The architecture comes with core security functions that protect the IP core of the processor. The crypto engine is embedded in the hardware design for securing the manifested data using an encrypted key management mechanism. It also protects the flash memory from the external hardware breeches. 

Real-Time Clock (RTC) is centrally connected to the internal peripheral bus for keeping track of real-time operations during extensive processing. The remote control signal receiver (REMC) triggers the system by detecting the external signals and communicates to the entire architecture via an internal peripheral bus.

You can head over to the product page of Renesas RX671 MCUs for detailed information on hardware specifications.