Designing in-home display units with Atmel tech

In-home display (IHD) units play a critical role in helping customers reduce their energy usage by providing relevant stats in real-time. Indeed, IHD units are typically designed to acquire and display information via a sensor with built-in RF and/or PLC. A more effective method? Transmitting information from a smart meter using a home area network.

“IHD units vary in complexity, from simple wall-mounted segment LCD displays, up to battery-operated products with color TFT displays and touchscreens,” an Atmel engineering rep told Bits & Pieces. “Advanced IHDs can display not only consumption information, but energy consumption advice from energy providers. They can also support a variety of additional functions such as home automation.”

To be sure, IHD units typically support displays, connectivity via USB and RF, as well as low power and touch buttons or screens for a fully interactive user interface (UI). And that is why Atmel offers a wide range of versatile microcontrollers (MCUs) for IHDs, from entry-level 8-bit AVRs to a sophisticated ARM9 core with embedded LCD graphics display controllers.

“In short, Atmel’s MCUs help facilitate flexible touch solutions, from buttons and wheels to sophisticated touch-screens, all providing support for a wide range of user interface features and capabilities,” the Atmel engineering rep explained.

“Meanwhile, power line communications (PLC) system-on-a-chip (SoC) solutions with full digital implementation deliver best-in-class sensitivity, high performance and high temperature stability. Plus, our CryptoAuthentication lineup provide a cost-effective, easy-to-implement security solution that is critical for wireless communication between meters and  IHD units.”

In terms of power efficiency, Atmel offers a number of advanced capabilities, including 1 µA watchdog and brown-out, picoPower tech for extended battery life, an event system to allow measurement while CPU is in SLEEP mode, support for true 1.6V operation, low-power RF transceivers for connectivity and the lowest power 32 kHz crystal oscillator (650nA RTC).

“In-house display units can range from a basic segment LCD to a more sophisticated color TFT. Depending on the display choice drivers and required  processing power, the primary microcontroller can be either an entry-level 8- or 32-bit MCU, scaling up to a more powerful embedded MPU with on-chip TFT LCD controller,” the engineering rep added.

“As products become more sophisticated, so will the UI. Atmel touch technology provides robust support for state of the art features such as capacitive touch buttons or a full touchscreen. The communications within the IHD depend on the implemented architecture of the HAN (typically RF or PLC). Of course, wireless connectivity can also be supported via Secure Digital Input Output (SDIO) cards.”

Interested in learning more about designing in-home display units with Atmel tech? Be sure to check out our extensive device breakdown here.

Atmel’s SAM4L ARM MCU tech powers game controllers

Atmel’s SAM4L ARM-based microcontroller lineup redefines the MCU power benchmark, delivering the lowest power in both active (90µA/MHz) and sleep modes – 1.5µA with full random access memory (RAM) retention and 700nA in back-up mode.

Simply put, the SAM4L lineup is the most efficient MCU tech available today, achieving up to 28 CoreMark/mA (using the IAR Embedded Workbench), while also offering the industry’s shortest wake-up time at 1.5µs from deep-sleep mode.

The SAM4L is targeted at a wide variety of portable and battery-powered consumer, industrial and medical applications.

However, the MCU lineup can also be used to power next-gen game controllers, along with related Atmel tech like the AT24C/AT25/AT93C serial EEPROM and ATR2406 RF transceiver.

On the software side, designers can look forward to an extensive ecosystem from Atmel and its partners, with an integrated development environment (IDE) and compiler (Studio 6 is free and integrated), along with multiple libraries.

And last, but certainly not least, there are also production-ready software packages available for drivers, software services and libraries. Interested? Additional information can be found on Atmel’s SAM4L MCU page here.

A closer look at Atmel’s picoPower technology

We briefly touched on Atmel’s picoPower technology this morning in the context of Samsung’s Galaxy S4 smartphone, which is equipped with Atmel’s sensor hub management MCU (microcontroller unit). The MCU collects and processes data from all connected sensors in real-time, optimizing multiple user experiences, such as gaming, navigation and virtual reality.

Atmel’s sensor hub MCU also lowers the overall system power consumption via picoPower technology to prevent drain and enable longer battery life. In a broader sense, it is important to note that all Atmel AVR picoPower devices are designed from the ground up for low power consumption utilizing the company’s proprietary low leakage processes and libraries to provide minimal power sipping in all sleep modes.

“An easy way to reduce power consumption in any design is to lower the operating voltage. But this would be mostly useless if analog performance was compromised,” an Atmel engineering rep told us. “Central to the AVR picoPower technology are carefully designed analog functions that continue to operate all the way down to 1.62V.”

To be sure, the various features of a microcontroller traditionally become unstable or even unusable at different voltage levels, as inaccuracies in analog peripherals, limited operation or an inability to write to non-volatile memory prevents designs from running at lower voltages. This leads to shorter battery life, larger and more expensive batteries, or a lot time spent trying to find workarounds for something that should be addressed by the microcontroller to begin with.

As such, Atmel AVR microcontrollers offer true 1.62 V operation, including all analog modules, oscillators, and flash and EEPROM programming. Meaning, various microcontroller features will not shut down one by one as the voltage drops.

“You can run the same application at different voltages without making comprises. All peripherals are available regardless of supply voltage,” the engineering rep continued. “The ADC, for example, can be used to measure the supply voltage as the cutoff voltage is approached, and when detected, it enables the application to store vital information and ensure a safe shutdown, enabling a glitch-free restart after changing batteries.”

Remember, power consumption is proportional to supply voltage, so running at as low a supply voltage as possible saves power. For battery operated devices, the Atmel AVR microcontroller can make use of the remaining power available at lower battery voltage levels as the battery depletes.

In addition to true 1.62 V operation, Atmel’s AVR peripherals with picoPower are capable of determining if incoming data requires use of the CPU or not. This feature is aptly dubbed SleepWalking, as it allows the CPU to sleep peacefully until an important event occurs, eliminating millions of false CPU wakeups. This means the CPU is no longer required to check whether or not a specific condition is present, such as an address match condition on the TWI (I2C) interface, or a sensor connected to an ADC that has exceeded a specific threshold.

Of course, entering sleep mode shuts down parts of the microcontroller to save power. Most oscillators and clocks consume a considerable amount of power when in use, and when waking up from sleep modes, these clocks need to be stable before they can be used. Waiting a long time for the clocks to be available and stable results in wasted power.

However, the Atmel AVR microcontroller is capable of waking up from sleep mode in 8 clock cycles when running from the internal RC oscillator. Moreover, a digital frequency locked loop (DFLL) replaces the traditional phase locked loop (PLL) to provide a programmable internal oscillator that is much faster and accurate.

It can also eliminate external components, which reduces the total system power consumption even more. When in sleep mode with the synchronous clocks turned off, the microcontroller can still wake up from asynchronous events such as a pin change, data received or even an I2C bus address match – enabling multiple wake-up sources from even the deepest sleep modes.

As noted above, the benefits of picoPower are clearly illustrated by Samsung’s decision to equip its flagship Galaxy S4 smartphone with Atmel’s sensor hub MCU which features picoPower tech.

“Atmel allows Galaxy S4 users the ability to enjoy applications requiring real-time motion sensing, without ever compromising battery life,” said Ingar Fredriksen, Senior Director of Flash-based Microcontrollers, Atmel Corporation. “ We look forward to teaming with Samsung on future designs.”

SleepWalking Helps Conserve Energy

Imagine you are the sole care-provider for a household full of babies all under the age of 3.  Each and every single one of them requires you to tend their needs and desires.  From feeding to going to the bathroom, from burping to changing their diapers, from bathing to putting them to nap/sleep to keeping them entertained, you are needed every single step of the way.  Isn’t that just exhausting?  Fast forward by a decade when they are grow to become teenagers – autonomy and self-sufficiency – in which they can all satisfy their own basic needs without your help, unless it’s an urgent matter.  Now you have much more free time to read a book, surf the net, get a job, or take a nap.

In essence, this is what SleepWalking is all about in the realm of an Atmel MCU.  Traditionally a technology found in the AVR architecture only, it is now incorporated into the ARM architecture as well.  It is a feature that extends the concept of autonomous peripherals (babies) that operate independently of the CPU core (a parent or care-provider) during active mode, to actually keeping the peripherals functional when the system clock has been stopped. This is achieved by clocking the peripherals using the real‐time clock (RTC), instead of the system clock.

In the SAM4L, SleepWalking has been integrated into many of the peripherals, including the analog comparator, the ADC, the I2C, UART and the capacitive touch interface. It is then the peripheral that decides whether to wake the system, instead of the CPU waking periodically to carry out an interrupt service routine.  With this feature, the need to wake the CPU reduces significantly thus allowing it to stay inactive for longer and more frequent and thereby conserving more energy.

For more information, check out this video for a more detailed explanation on SleepWalking.  Please note: despite the AVR UC3 being used as an example in the video, the underlying fundamentals of how SleepWalking works and its benefits are the same as in the ARM SAM4L.