Tag industrial panel pc

Voice Control Panel PC

Building Skill-free Alexa Voice Control into IoT Devices

Voice Control Panel PC

Voice control is the successor of touch screen interface used in products like smartphones, tablets, home automation, in-vehicle control, vending machines, kiosk and Human Machine Interface (HMI).  It is the next big thing of user Interface (UI), especially for artificial intelligence enabled IoT devices, ranging from smart home products to industrial control panels.  According to ABI Research, “last year, 141 million voice control smart home device shipped worldwide.”  In 2020, “voice control device shipments will grow globally by close to 30% over 2019.”

Since the original Echo device was brought to market in 2014, Amazon’s Alexa Voice Service (AVS) is becoming one of the most popular voice recognition and natural language understanding (NLU) artificial intelligent services for building connected voice control IoT devices. These devices are defined as Alexa built-in products. They can be built with industrial computers, panel PCs, tablet computers or other embedded systems with microphones, speaker and Internet connection. With these products, you can initiate with your voice commands, get responses from Alexa, connect to the cloud and control peripherals with your voice.

Besides embedded control system layers like hardware, operating system and application software, the design of a Alexa built-in product also involves voice front end, Wake Word Engine (WWE), Alexa Voice Service (AVS) cloud services, AVS Device SDK integration, extra communication and control interfaces.

Selecting a Voice Front End

Voice front end is the forefront of a voice control device which mandates high-accuracy of picking up human voice in a noisy environment.  To ensure wake-word triggering and provide clear voice commands for interpretation, a typical voice front end consists of software or hardware DSPs to implement technologies like Acoustic Echo Cancellation (AEC), Beamforming, noise suppression and Wake Word Engine (WWE). 

Loud music or speech playing back by the device is picked up by its microphones.  Acoustic Echo Cancellation (AEC) subtracts the playback noise and allows the microphones to pick up voice commands.  Beamforming uses multiple microphones to locate the source of speech and attenuates all other background noises.  Noise suppression removes background noise to improve voice recognition. The Wake Word Engine WWE listens for the keyword (like “Alexa”) before taking action to send the following utterance for speech recognition and understanding.

Estone’s EMB-2238 reference design is one of the examples of voice front end solution.  It has built-in Amazon-qualified hardware DSP smart codec for AEC, noise suppression, high performance digital MEMS mic array for omni-directional spatial capture and support of Sensor’s TrulyHandsfre wake word engine tuned to “Alexa”.

Voice Front End

Embedding Alexa Voice Service (AVS)

Alexa Voice Service (AVS) is a cloud-based service that allows device developers to integrate Alexa features and functions into a connected voice enabled product. It provides access to complex speech recognition, natural language understanding, Alexa skills and capabilities in the cloud for Alexa built-in products.

After selecting the voice front end with sufficient memory, processing power and a wake word-enabled microphone array, the next step for the developers is the integration of Alexa Voice Service Device SDK. The AVS Device SDK consists of C++ based libraries to communicate with the cloud-based Alexa Voice Service. It also exposes AVS APIs for device application customizations.

Let’s say that when a user asks “Alexa, turn on the AC”. The Wake Word Engine detects the keyword “Alexa” and the device’s AVS API sends the audio as a sound clip (event) to Alexa Voice Service in the cloud. AVS validates the wake-word and uses automatic speech recognition (ASR) to turn the voice command into text. Then, the natural-language understanding (NLU) process interprets what the user wants and routes it to the appropriate skill and action defined in the cloud. AVS then sends the voice of Alexa via text-to-speech engine or action messages back to the device AVS interface as directives.

AVS Device SDK

AVS Device SDK runs on Linux, Android, Windows and macOS.  This video demonstrates the Alexa Voice Service integrated into a Yocto Linux based EMB-2238 voice control reference design.

Building Skill-free Alexa Voice Control

More and more developers are building IoT devices using voice to control their unique hardware or custom peripherals. These products are not just as simple as controlling single-function smart light bulbs or smart plugs. For example, a recreational vehicle (RV) control panel controls HAVC, lighting, exhaust fans, generator, awning and many more. The peripherals being controlled are often connected via CAN bus, serial ports like RS-232/485, general-purpose input/output (GPIO) or wireless communication like WiFi, Zigbee, Z-Wave, etc.

The standard way for the developers to add Alexa voice control into their products is to build separate custom Alexa Skills for their devices and maintain them in a separate cloud. That device maker’s cloud is then used to interface to Alexa Voice Service cloud and the connected device with peripherals being controlled (Figure 1).

Skill-free Alexa Voice Control

However, in many cases, the products being developed may only have a few simple control interface type like the following:

  • Power – control the on and off a connected peripheral, such as turning on/off the exhaust fan.
  • Toggle – switch between two states, such as open or close the awning.
  • Range – set the range of continuous values of a peripheral property, such as setting the temperature of the HAVC.
  • Mode – set a set of values of a device’s operation mode, such as the theme of the ambient lighting.

These control interfaces are part of the Alexa Smart Home Skill API capability interfaces.  With the latest AVS Device SDK, developers can enable these smart home capabilities and add skill-free custom voice control functionality for their AVS devices.  Products running AVS client with Smart Home over AVS enabled can send and receive “Smart Home” events and directives for voice control with a single connection to the Alexa cloud (Figure 2, 3).  This video is a demonstration of Estone’s 7” PPC-4707 POE Panel PC development kit built with skill-free Alexa voice control.

Voice control technology redefines the Internet of Things. Many companies are choosing to use the Alexa Voice Service (AVS) to add voice control capability to their products.  Efforts are underway to simplify the development experience, like providing qualified voice front end reference designs, creating integrated AVS voice control development kits and the introduction of skill-free Smart Home for AVS Device SDK, helping developers to get their voice-enabled designs to market faster.  Get your project started now.

To know more about Estone’s AVS voice control reference design products, see Embedded ARM Boards and Industrial Panel PCs on our website or contact us for details of your project.

Touch panel ESD protection

Touch panel ESD protection for medical tablet and panel PC

Industrial panel PC with ESD protection

With the evolution of touch screen technology, touch interface has been gradually taking its place in life as one of the most effective user interfaces. We have become accustomed to using electronic products like our own smartphones, tablets and kiosks, ATMs, vending machines, electronic information systems in public places with touch screens. The healthcare industry is another area with rapid adoption of medical tablets, touch panel PCs, medical devices with touch panels and other touch related medical computers.

As any user accessible areas can be subjected to Electrostatic Discharge (ESD) strikes, all products with touch panels require some sort of ESD protection. Their electrostatic discharge problems need to be addressed to meet international standards. Electrostatic discharge can be very harmful to computer systems. Even a small amount of voltage can damage components and cause system failure.

Product reliability is an important factor for hardware and software on the design of industrial panel PC and medical tablet computers with touch panels built-in. This article will provide information on touch panel ESD protection, Electromagnetic Compatibility (EMC) standard ESD tests and requirements for medical devices and industrial computers.

Touch panel ESD protection

A typical projective capacitive touch panel consists of three major components, a glass protective cover, a capacitive touch sensor layer and a touch controller circuit. The touch controller circuit traditionally exists on a separate FPC. On one side of the FPC, the touch controller IC is responsible for monitoring the electric field around the panel with a series of electrodes in the touch sensor. If an object is placed in close proximity, it detects the change and records the location information.

Touch panel ESD protection

The touch controller is designed to sense electrical variation on the surface of the panel. The environment or human with large electrostatic charge to touch the panel will let the controller sensed a huge noise. The touch sensor pins of the touch controller IC will inevitably contain ESD protection circuits. The huge trigger signal will send through the ESD protection circuit and flow into the power or ground lines of the controller.

On the other hand, the FPC connection to the main board can also expose the touch controller to ESD pulses introduced at the system level. Examples of these ESD channels include USB, Ethernet or other exposed interfaces of the system. When the power increases to more than the touch controller IC’s ESD protection limit, it will damage the IC, or cause internal circuit malfunction.

To solve the problem of electrostatic discharge with touch panels, many techniques can be applied, including mechanical design, production control, system circuit or component characteristic design. The basic principle is to protect the key components like the touch controller IC. Most EMC hardware design measures can be applied to ESD immunity improvement for touch panels, including power supply design, layout considerations, I2C pull up considerations, metal part grounding, adding external ESD protection, etc.

In addition to hardware measures, software measures can also be implemented to deal with some other touch panel related ESD problems. For example, in our touch panel PCs PPC-4310, touch controller ESD watchdog feature of the firmware is enabled. It allows the reset of the touch controller and recovery of the touch function from non-destructive ESD events.

Tablet computer and panel PC ESD tests

Electrostatic discharge (ESD) tests for tablet computers and industrial panel PCs for measuring ESD are based on IEC 61000-4-2. It defines the range of test levels in relation to different environmental and installation conditions and establishes the appropriate test procedures. The objective of the standard is to establish a common reproducible basis for evaluating the performance of equipment subjected to ESD protections.

There are two types of tests based on the international standard, contact discharge and air discharge. The following is an IEC 61000-4-2 specifying compliance levels of ESD tests. A common test level for industrial panel PCs is 6kV contact, 8kV air, but these values could be higher or lower depending on the product standard requirements.

IEC 61000-4-2 ESD test classification:

IEC 61000-4-2 ESD test classification

Where “x” can be any level in between the other levels.

Medical tablet and panel PC ESD test requirements

The new EMC standard for medical devices, such as medical tablets and panel PCs is IEC 60601-1-2 standard. It includes increased testing limits for electrostatic discharge (ESD), radiated radio-frequency (RF) immunity, surge immunity, and electrical fast transients (EFTs). The standard outlined in IEC 60601-1-2 for measuring ESD is following IEC 61000-4-2 mentioned above.

Touch panel ESD protection for medical tablet PCs

One of the significant revisions to the immunity standard IEC 60601-1-2 is the increased ESD level. The contact discharge level is increased from 6kV to 8kV, while air discharge level is increased from 8kV to 15kV. This is the same as the Class 4 of the IEC 61000-4-2 standard.

Estone’s medical grade tablet computers and industrial panel PCs go through a series of rigorous product development processes. They are designed to meet IEC 61000-4-2 or IEC 60601-1-2 ESD test standards for product quality and reliability to use in the medical field.

To know more about our products in these categories, see medical tablets and panel PCs on our website or contact us for details of your project.