Tag Archives: Human Machine Interface

Touch-sensing HMI

The key element in the consumer appeal of wearable devices lies in their touch-sensing HMI or human-machine interface—it provides an intuitive and responsive way of interacting via sliders and touch buttons in these devices. Wearable devices include earbuds, smart glasses, and smartwatches with a small touchscreen.

An unimaginable competition exists in the market for such types of wearable devices, continually driving innovation. The two major features over which manufacturers typically battle for supremacy and which matter particularly to consumers are—run time between battery charges, and the form factor. Consumers typically demand a long run-time between charges, and they want a balance between convenience, comfort, and a plethora of features, along with a sleek and attractive design. This is a considerable challenge for the designers and manufacturers.

For instance, while the user can turn off almost all functions in a wearable device like a smartwatch for long periods between user activity, the touch-sensing HMI must always remain on. This is because the touch intentions of the user are randomly timed. They can touch-activate their device any time they want to—there is no pattern that allows the device to know in advance when the user is about to touch-activate it.

Therefore, the device must continuously scan to detect a touch for the entire time it is powered up, leading to power consumption by the HMI subsystem, even during the low-power mode. The HMI subsystem is, therefore, a substantial contributor to the total power consumed by the device. Reducing the power consumption of the touch system can result in a substantial increase in the run-time between charges of the device.

Most wearable devices use the touch-sensing HMI as a typical method for waking up from a sleep state. These devices generally conserve power by entering a low-power touch detect function that operates it in a deep sleep mode. In this mode, the scanning takes place at a low refresh rate suitable for detecting any kind of touch event. In some devices, the user may be required to press and hold a button or tap the screen momentarily to wake the device.

In such cases, the power consumption optimization and the amount of power saved significantly depends on how slow it is possible to refresh the sensor. Therefore, it is always a tradeoff between a quick response to user touch and power consumption by the device. Moreover, touch HMI systems are notorious for the substantial amount of power they consume.

Commercial touch-sensing devices typically use microcontrollers. Their architecture mostly has a CPU with volatile and non-volatile memory support, an AFE or analog front-end to interface the touch-sensing element, digital logic functions, and I/Os.

The scanning operation typically involves CPU operation for initializing the touch-sensing system, configuring the sensing element, scanning the sensor, and processing the results to determine if a touch event has occurred.

In low-power mode, the device consumes less power as the refresh rate of the system reduces. This leads to fewer scans occurring each second, only just enough to detect if a touch event has occurred.

ARM9 SBC with 7-inch Touchscreen

Now you can have complete HMI or Human Machine Interface with the Linux-ready ARM9 Single Board Computer from Premier Farnell. It comes with a 7-inch touchscreen and you can use the SBC for home automation as well.

The EDM6070AR-01 is a single board computer with an integrated Embedded Display Module or EDM, which makes it suitable for supporting a variety of embedded HMI applications. These include data acquisition and analysis, network terminals, medical products, intelligent instruments and industrial control terminals. Farnell has included a Smart Home demo application with the SBC and it features a smart-LED controller. With the home automation application, users can set light levels independently in each room. Additionally, they can also set flexible states for humidity and temperature using the smart-climate feature. Moreover, the SBC also allows management of room-specific surveillance cameras and audio streaming.

The brain behind the EDM6070AR-01 single board computer is the Mini6935 COM or Computer-On-Module, which is based on the ATMEL ARM9 processor AT91SAM9X35. Compared with the SAM9G35, the 400MHz SAM9X35 is more advanced, offering 16KB each of data and instruction cache along with additional interfaces such as UART, ISI and CAN. However, unlike the closely related SAM9X25, the SAM9X35 does not have a second Ethernet controller, but adds a second CAN interface along with an LCD interface.

Within the Mini6935 COM are 256MB of NAND flash, 128MB of DDR2 SDRAM, 4MB of data flash and 4KB EEPROM. The COM has a 10/100 Ethernet MAC, while it routes all signals via two rows of connectors on the back of the module.

The EDM6070AR-01 includes an 800×600-pixel LCD controller, two USB host ports, a USB device port and two SD card interfaces. One hundred and eight GPIOs, dual SPI and CAN interfaces form the industrial IOs. The EBM6070AR-01 SBC ships with a Linux 2.6.39 BSP supporting QT GUIs and numerous file systems.

The 108 GPIOs are each 32-bits, of which three are peripheral IOs, and the rest are programmable multiplexed. The SBC is also equipped with a 12-channel, 10-bit ADC for the touchscreen and a 4-channel, 16-bit PWM controller. With dimensions of 64x45mm and running on 3.3V, 1.25A power, the SBC has a watchdog, can operate as a soft modem, and perform safely within a temperature range of 10-70°C. Apart from this, the EDM6070AR-01 also integrates three GPIO inputs and outputs along with various LEDs, buttons and buzzers.

The 800×480-pixel, 7-inch touchscreen stacks on top of the board. The LCD module is TFT, with 800×480, 24-bit resolution and a 4-wire resistive touch panel. The SBC networks through a fast Ethernet port controlled by a DM9161CIEP chip. Other features include two power LEDs, an IO button and Reset button, RTC with battery backup and a watchdog. The SBC also provides an output DC supply of 5V.

Among the real-world ports available on the EDM6070AR-01 are a USB high-speed host port, a USB device port, Audio in-out, Debug interface, RS232 interface, RS485 interface and CAN interface.
You can drop the EDM6070AR-01 SBC into your product with negligible integration efforts. It is also possible to wrap an enclosure around it, add software applications and allow it to become your finished product.

HMI: How to Communicate With Machines

Accelerating quality, quantity, economic efficiencies and environmental protection are leading to an increasingly connected process flow and factory floor. In combination with decreased personnel, that has led to processing of increased amounts of information by fewer and less application-specific operators in the control center. It requires a well-designed HMI or Human Machine Interface system to decrease the gap between the production process and the operator via an intuitive visualization system, layers of detail that allow a bird’s eye view down to the minute details, and includes training material and documentation that the operator has on his fingertips.

A well-designed HMI system provides numerous benefits. Chief among them are increased safety, quantity, quality and economic efficiency. Apart from minimizing the risk of disruption in the production process, HMI systems also reduce the over downtime while allowing fewer operators to manage more information with less field-specific knowledge.

HMI provides a means of monitoring, controlling, managing and/or visualizing device processes. For example, an operator panel may allow the operator of an industrial machine to interact with the machine in a visual, graphical way. The operator can easily control the machine by using the touch screen or external buttons, as all readouts and controls readouts are graphically displayed on the screen.

HMIs can be located on the machine, in the form of simple segmented displays or LCD panels of high-resolution. They can be located in portable handheld devices that are battery operated or in centralized control rooms. Machines and process controls can use them to connect the operator with Programmable Logic Control application systems to control sensors, actuators and machines on the factory floor.

For communicating with industrial machines, the usability of the HMI system depends on the processing power of the system, its ability to render reality-like complex screens, quick responses to user inputs and the flexibility for handling several levels of operator interactions. Usually, effective communication requires the HMI to have dynamically changing graphics. This in turn, requires the system to be a high-performance type that supports various resolutions and displays of high refresh rates. For efficient communication between the operator, numerous machines and control systems, it is imperative that multiple connectivity and protocols must be supported.

Industrial automation thrives on real-time communication. Using industrial micro-controllers along with PRU-ICSS or programmable industrial communication subsystems makes it possible to support various popular, certified serial protocols, including those that are Ethernet-based. The PRU-ICSS allows HMI manufacturers easily support industrial communication protocols of multiple types on a single hardware platform. The most important advantage of this platform is that it does not require the support of external ASICs and FPGAs. This offers huge scaling in performance and the integration offers opportunities of software and design reuse.

Portable HMI solutions use several wireless connectivity solutions such as WLAN, Sub-1GHz, ZigBee and BlueTooth. This broad portfolio offers the maximum flexibility when designing for wireless. For example, the WiLink 8 solution provides high-performance BlueTooth and Wi-Fi in one module. The Sub-1GHz performance line is very popular and the most reliable in its range.

What is Human Machine Interface: HMI?

Accelerating quality, quantity, economic efficiencies and environmental protection are leading to an increasingly connected process flow and factory floor. In combination with decreased personnel, that has led to processing of increased amounts of information by fewer and less application-specific operators in the control center. It requires a well-designed HMI or Human Machine Interface system to decrease the gap between the production process and the operator via an intuitive visualization system, layers of detail that allow a bird’s eye view down to the minute details, and includes training material and documentation that the operator has on his fingertips.

A well-designed HMI system provides numerous benefits. Chief among them are increased safety, quantity, quality and economic efficiency. Apart from minimizing the risk of disruption in the production process, HMI systems also reduce the over downtime while allowing fewer operators to manage more information with less field-specific knowledge.

HMI provides a means of monitoring, controlling, managing and/or visualizing device processes. For example, an operator panel may allow the operator of an industrial machine to interact with the machine in a visual, graphical way. The operator can easily control the machine by using the touch screen or external buttons, as all readouts and controls readouts are graphically displayed on the screen.

HMIs can be located on the machine, in the form of simple segmented displays or LCD panels of high-resolution. They can be located in portable handheld devices that are battery operated or in centralized control rooms. Machines and process controls can use them to connect the operator with Programmable Logic Control application systems to control sensors, actuators and machines on the factory floor.

For communicating with industrial machines, the usability of the HMI system depends on the processing power of the system, its ability to render reality-like complex screens, quick responses to user inputs and the flexibility for handling several levels of operator interactions. Usually, effective communication requires the HMI to have dynamically changing graphics. This in turn, requires the system to be a high-performance type that supports various resolutions and displays of high refresh rates. For efficient communication between the operator, numerous machines and control systems, it is imperative that multiple connectivity and protocols must be supported.

Industrial automation thrives on real-time communication. Using industrial micro-controllers along with PRU-ICSS or programmable industrial communication subsystems makes it possible to support various popular, certified serial protocols, including those that are Ethernet-based. The PRU-ICSS allows HMI manufacturers easily support industrial communication protocols of multiple types on a single hardware platform. The most important advantage of this platform is that it does not require the support of external ASICs and FPGAs. This offers huge scaling in performance and the integration offers opportunities of software and design reuse.

Portable HMI solutions use several wireless connectivity solutions such as WLAN, Sub-1GHz, ZigBee and BlueTooth. This broad portfolio offers the maximum flexibility when designing for wireless. For example, the WiLink 8 solution provides high-performance BlueTooth and Wi-Fi in one module. The Sub-1GHz performance line is very popular and the most reliable in its range.