Tag Archives: low power microcontroller

The power of the platform in IoT and wearable designs

What IoT developers want? A candid look at the wearable designs shows how platform approach is helping design engineers confront daunting challenges in the IoT arena.

“Providers become platforms” is the second most prominent finding of the Forbes story entitled “The Five Most Disruptive Innovations at CES 2016.” Interestingly, all the five disrupting forces outlined in the story relate to the Internet of Things blaze one way or the other. A coincidence? Not really.

CES 2016 was mostly about demonstrating how the advent of a connected world is possible with the creation of an array of smart and interconnected devices. However, the IoT juggernaut, while exploring the true value of connectivity, also requires new business models, which in turn, makes time-to-market even more critical.

Smart badge brings efficiency in enterprise, hospitality and healthcare

Take smart wearable devices, for instance, which were arguably the biggest story on the CES floor this year. A wearable design comprises of one or more sensors, connectivity solution like a radio controller, a processor to carry out system-level functions, storage to log information, display and battery. And what IoT and wearable developers want?

A platform that allows them to facilitate the finished products quickly and efficiently. The design engineers simply can’t afford experimentation with the basic blocks as they need a precedence of basic hardware and software functions working efficiently and smoothly.

Anatomy of Wearable Design

First and foremost, wearable designs confront power constraints even greater than mobile devices. Not surprisingly, ultra-low-power MCUs lie at the heart of wearable designs because they combine flash, on-chip RAM and multiple interface options while intelligently turning power on and off during activity and idle periods, respectively.

The next design conundrum relates to the form factor because these devices are being worn, so they have to be small and light. That, in turn, demands even smaller circuit boards with a greater level of integration. Enter the IoT platforms.

Amid power, performance and form factor considerations, the choice of a right IoT platform means that designers will most likely get the basic building blocks right. And that will allow IoT developers to focus on the application, differentiation and customer needs.

That’s what Atmel is aiming for with the launch of a reference platform for cost-optimized IoT and wearable applications. Atmel’s ultra-low-power platform, which was announced over the week of CES, is aimed at battery-operated wearable devices requiring activity and environment monitoring.

Power has a critical role in the key IoT building blocks

IoT Developer Platform

Below are the key highlights of Atmel’s platform offering for the IoT and wearable designs.

Processor: Microcontroller’s low-power requirements make it a likely choice in wearable designs; MCUs that communicate and process sensor inputs draw very little power from the battery while asleep. Remember the L21 microcontroller that made headlines back in 2015 after leading the low-power benchmarks conducted by EEMBC ULPBench.

Atmel’s SMART SAM L21 MCU — based on ARM’s lowest power Cortex-M0+ processing core — scored 185 in the benchmark and was able to bring the power consumption down to 35µA/MHz in active mode and 200nA in sleep mode.

Communications: The BTLC1000 is an ultra-low power Bluetooth Smart (BLE 4.1) system-on-chip (SoC) that comes integrated with ARM Cortex-M0 core, transceiver, modem, MAC, power amplifier, TR switch, and power management unit (PMU). It can be used as a BLE link controller or data pump with external host MCU or as a standalone applications processor with embedded BLE connectivity and external memory.

Atmel claims that its BTLC1000 Bluetooth solution — a 2.2mm x 2.1mm wafer level chip scale package — is 25 percent smaller than the nearest competitor solution. And Electronic Products magazine has corroborated that premise by calling it the lowest power BLE chipset that consumes less than 4mA in RX and less than 3mA in TX at 0dbm.

Security: Atmel is among the first chipmakers to offer specialized security hardware for the IoT market. Its microcontrollers come integrated with anti-cloning, authentication and encryption features.

Display: Wearable devices often show data such as time, measurements, maps and notifications on a display, and here, capacitive touch provides a very intuitive form of interfacing with the information. Atmel’s MCUs can directly manage capacitive buttons through software libraries that the firm provides.

Furthermore, Atmel offers standalone display controllers that support capacitive button, slider and wheel (BSW) implementations. These touch solutions can be tuned to moisture environments, a key requirement for many wearable applications. Atmel’s maXTouch capacitive touchscreen controller technology is a leading interface solution for its low-power consumption, precision and sensitivity.

Sensors: The development framework for the wearable designs features BHI160 6-axis SmartHub motion sensor and BME280 environment sensor from Bosch. It’s worth noting that Bosch is one of Atmel’s sensor partners. However, wearable product designers are free to pick sensors of their choice from Atmel’s other sensor partners.

Software support: The software package includes RTOS, Atmel’s Studio 7 IDE and Atmel START, which Atmel claims is the world’s first intuitive web-based tool for software configuration and code generation. Moreover, Atmel Software Framework (ASF) offers communication libraries for Bluetooth radios.

Atmel's developer platform for IoT and wearable designs

The truth is that the design game has moved from hardware and software functional blocks to complete developer ecosystems since the iPhone days. Now the ecosystem play is taking platforms to a whole new level in the design diversity that comes with the IoT products.

The choice of a right IoT platform means that designers will most likely get the basic building blocks right, and then, they can focus on the application and customer needs. It also provides design engineers space for differentiation, a critical factor in making wearable devices a consumer success.



Atmel’s SAM L21 MCU for IoT tops low power benchmark

SAM L21 MCUs consume less than 940nA with full 40kB SRAM retention, real-time clock and calendar, and 200nA in the deepest sleep mode.

The Internet of Things (IoT) juggernaut has unleashed a flurry of low-power microcontrollers, and in that array of energy-efficient MCUs, one product has earned the crown jewel of being the lowest-power Cortex M-based solution with power consumption down to 35µA/MHz in active mode and 200nA in sleep mode.

How do we know if Atmel’s SAM L21 microcontroller can actually claim the leadership in ultra-low-power processing movement? The answer lies in the EEMBC ULPBench power benchmark that was introduced last year. It ensures a level playing field in executing the benchmark by having the MCU perform 20,000 clock cycles of active work once a second and sleep the remainder of the second.


 ULPBench shows SAM L21 is lower power than any of its competitor's M0+ class chips

ULPBench shows SAM L21 is lower power than any of its competitor’s M0+ class chips.

Atmel has released the ultra-low-power SAM L21 MCU it demonstrated at Electronica in Munich, Germany back in November 2014. Architectural innovations in the SAM L21 MCU family enable low-power peripherals — including timers, serial communications and capacitive touch sensing — to remain powered and running while the rest of the system is in a reduced power mode. That further reduces power consumption for always-on applications such as fire alarms, healthcare, medical and connected wearables.

Next, the 32-bit ARM-based MCU portfolio combines ultra-low-power with Flash and SRAM that are large enough to run both the application and wireless stacks. Collectively, these three features make up the basic recipe for battery-powered mobile and IoT devices for extending their battery life from years to decades. Moreover, they reduce the number of times batteries need to be changed in a plethora of IoT applications.

Low Power Leap of Faith

Atmel’s SAM L21 microcontrollers have achieved a staggering 185.8 ULPBench score, which is way ahead of runner-up TI’s SimpleLink C26xx microcontroller family that scored 143.6. The SAM L21 microcontrollers consume less than 940nA with full 40kB SRAM retention, real-time clock and calendar, and 200nA in the deepest sleep mode. According to Atmel spokesperson, it comes down to one-third the power of competing solutions.

Markus Levy, President and Founder of EEMBC, credits Atmel’s low-power feat to its proprietary picoPower technology and the company’s low-power expertise in utilizing DC-DC conversion for voltage monitoring. Atmel’s picoPower technology employs flexible clocking options and short wake-up time with multiple wake-up sources from even the deepest sleep modes.

ULPBench aims to provide developers with a reliable methodology to test MCUs

ULPBench aims to provide developers with a reliable methodology to test MCUs.

In other words, Atmel has taken the low-power game beyond architectural improvements to the CPU while optimizing nearly every peripheral to operate in standalone mode and then use a minimum number of transistors to complete the given task. Most lower-power ARM chips simply disable the clock to various parts of the device. The SAM L21 microcontroller, on the other hand, turns off power to those chip parts; hence, there is no leakage current in thousands of transistors in that part.

Here is a brief highlight of Atmel’s low-power development efforts that now encompass almost every peripheral in an MCU device:

Sleep Modes

Sleep modes not only gate away the clock signal to stop switching consumption, but also remove the power from sub-domains to fully eliminate leakage. Atmel also employs SRAM back-biasing to reduce leakage in sleep modes.

Consider a simple application where the temperature in a room is monitored using a temperature sensor with the analog-to-digital converter (ADC). In order to reduce the power consumption, the CPU would be put to sleep and wake up periodically on interrupts from a real-time counter (RTC). The measured sensor data is checked against a predefined threshold to decide on further action. If the data does not exceed the threshold, the CPU will be put back to sleep waiting for the next RTC interrupt.


SleepWalking is a technology that enables peripherals to request a clock when needed to wake-up from sleep modes and perform tasks without having to power up the CPU Flash and other support systems. For instance, Atmel’s ultra-low-power capacitive touch-sensing peripheral can run in all operating modes and supports wake-up on a touch.

For the temperature monitoring application, as mentioned above, this means that the ADC’s peripheral clock will only be running when the ADC is converting. When the ADC receives the overflow event from the RTC, it will request its generic clock from the generic clock controller and peripheral clock will stop as soon as the ADC conversion is completed.

Event System

The Event System allows peripherals to communicate directly without involving the CPU and thus enables peripherals to work together to solve complex tasks using minimal gates. It allows system developers to chain events in software and use an event to trigger a peripheral without CPU involvement.

Again, taking temperature monitor as a use case, the RTC must be set to generate an overflow event, which is routed to the ADC by configuring the Event System. The ADC must be configured to start a conversion when it receives an event. By using the Event System, an RTC overflow can trigger an ADC conversion without waking up the CPU. Moreover, the ADC can be configured to generate an interrupt if the threshold is exceeded, and the interrupt will wake up the CPU.


Low Power MCU Use Case

Paul Rako has mentioned a sensor monitor in his recent post in Atmel’s Bits & Pieces blog. Rako writes in his post titled “The SAM L21 pushes the boundaries of low power MCUs” about this sensor monitor being asleep 99.99 percent of the time, waking up once a day to take a measurement and send it wirelessly to a host. Such tasks can be conveniently handled by an 8-bit device.

However, moving to IoT applications, which constitute protocol stacks, there is number crunching involved and that requires a faster ARM-class 32-bit chip. So, for battery-powered IoT applications, Rako makes the case for 32-bit ARM-based chip that can wake up, do its thing, and go back to sleep. If a high-current chip wakes up 10 times faster but uses twice the power, it will still use less energy and less charge than the slower chip.

Next, Rako presents sensor fusion hub as a case study in which the device saves power by skipping the radio chip to send the data from each sensor and instead uses the ARM-based microcontroller that does the math and pre-processing to combine the raw data from all sensors and then assembles the result as a simple chunk of data.

Atmel has scored an important design victory in the ongoing low-power game that is now prevalent in the rapidly expanding IoT market. Atmel already boasts credentials in the connectivity and security domains — the other two key IoT building blocks. Its connectivity solutions cover multiple wireless arenas — Bluetooth, Wi-Fi, Zigbee and 6LoWPan — to enable IoT communications.

Likewise, Atmel’s CryptoAuthentication devices come with protected hardware key storage and are available with SHA256, AES128 or ECC256/283 cryptography. The IoT triumvirate of low power consumption, broad connectivity portfolio and crypto engineering puts Atmel in a strong position in the promising new market of IoT that is increasingly demanding low power portfolio of MCUs to be matched with high performance.

Majeed Ahmad is author of books Smartphone: Mobile Revolution at the Crossroads of Communications, Computing and Consumer Electronics and The Next Web of 50 Billion Devices: Mobile Internet’s Past, Present and Future.

Atmel and IoT and Crypto, oh my!

One of the companies that is best positioned to supply components into the Internet of Things (IoT) market is Atmel. For the time being most designs will be done using standard components, not doing massive integration on an SoC targeted at a specific market. The biggest issue in the early stage of market development will be working out what the customer wants and so the big premium will be on getting to market early and iterating fast, not premature cost optimization for a market that might not be big enough to support the design/NRE of a custom design.

Latest product in Atmel's SmartConnect family, the SAM W25 module

Here is Atmel’s latest product in the SmartConnect family, the SAM W25 module

Atmel has microcontrollers, literally over 500 different flavors and in two families, the AVR family and a broad selection of ARM microcontrollers ad processors. They have wireless connectivity. They have strong solutions in security.

Indeed last week at Electronica in Germany they announced the latest product in the SmartConnect family, the SAM W25 module. It is the industry’s first fully-integrated FCC-certified Wi-Fi module with a standalone MCU and hardware security from a single source. The module is tiny, not much larger than a penny. The module includes Atmel’s recently-announced 2.4GHz IEEE 802.11 b/g/n Wi-Fi WINC1500, along with an Atmel | SMART SAM D21 ARM Cortex M0+-based MCU and Atmel’s ATECC108A optimized CryptoAuthentication engine with ultra-secure hardware-based key storage for secure connectivity.

Atmel at Electronica 2014

Atmel at Electronica 2014

That last item is a key component for many IoT designs. Security is going to be a big thing and with so many well-publicized breaches of software security, the algorithms, and particularly the keys, are moving quickly into hardware. That component, the ATECC108A, provides state-of-the-art hardware security including a full turnkey Elliptic Curve Digital Signature Algorithm (ECDSA) engine using key sizes of 256 or 283 bits – appropriate for modern security environments without the long computation delay typical of software solutions. Access to the device is through a standard I²C Interface at speeds up to 1Mb/sec. It is compatible with standard Serial EEPROM I²C Interface specifications. Compared to software, the device is:

  • Higher performance (faster encryption)
  • Lower power
  • Much harder to compromise

Atmel has a new white paper out, Integrating the Internet of Things, Necessary Building Blocks for Broad Market Adoption. Depending on whose numbers you believe, there will be 50 billion IoT edge devices connected by 2020.

Edge nodes are becoming integrated into everyone’s life

As it says in the white paper:

On first inspection, the requirements of an IoT edge device appear to be much the same as any other microcontroller (MCU) based development project. You have one or more sensors that are read by an MCU, the data may then be processed locally prior to sending it off to another application or causing another event to occur such as turning on a motor. However, there are decisions to be made regarding how to communicate with these other applications. Wired, wireless, and power line communication (PLC) are the usual options. But, then you have to consider that many IoT devices are going to be battery powered, which means that their power consumption needs to be kept as low as possible to prolong battery life. The complexities deepen when you consider the security implications of a connected device as well. And that’s not just security of data being transferred, but also ensuring your device can’t be cloned and that it does not allow unauthorized applications to run on it.
IoT Design Requirements - Software / Development Tools Ecosystem

IoT design requirements: Software / development tools ecosystem

For almost any application, the building blocks for an IoT edge node are the same:

  • Embedded processing
  • Sensors
  • Connectivity
  • Security
  • And while not really a “building block,” ultra-low power for always-on applications

My view is that the biggest of these issues will be security. After all, even though Atmel has hundreds of different microcontrollers and microprocessors, there are plenty of other suppliers. Same goes for connectivity solutions. But strong cryptographhic solutions implemented in hardware are much less common.

The new IoT white paper is available for download here.

This post has been republished with permission from SemiWiki.com, where Paul McLellan is a featured blogger. It first appeared there on November 19, 2014.

Intelligent MCUs for Low Power Designs

By Florence Chao, Senior Field Marketing Manager, MCU Business Development

Industrial and consumer devices using ARM® Cortex®-M4

Industrial and consumer devices using ARM® Cortex®-M4

Blood glucose meters, sport watches, game controllers and accessories, guess what they all have in common. Yes, like a lot of other industrial and consumer devices, they run on batteries and demand long or extended battery life. As an engineer, this translates into a key challenge when designing an embedded computing system. You need a central heart—in this case a microcontroller—that consumes as little power as possible in both active and static modes yet doesn’t sacrifice performance.  The Atmel® SAM4L ARM® Cortex®-M4 based series is designed with this in mind.

The SAM4L microcontroller redefines low power, delivering the lowest power consumption in its class in active mode (90uZ/MHz) as well as in static mode with full RAM retention running. It also delivers the shortest wake-up time (1.5us). At the same time, this is the most efficient microcontroller available today, achieving up to 28 CoreMark/mA.

The SAM4L series integrates Atmel’s proprietary picoPower® technology

The SAM4L series integrates Atmel’s proprietary picoPower® technology

The SAM4L series integrates Atmel’s proprietary picoPower® technology, which ensures the devices are developed from the ground up—from transistor design to clocking options—to consume as little power as possible. In addition, Atmel Sleepwalking technology allows the peripherals to make intelligent decisions and wake up the system upon qualifying events at the peripheral level.

In this video, you will see how the SAM4L microcontroller supports multiple power configurations to allow the engineer to optimize its power consumption in different use cases. You will also see another good feature of the SAM4L series, Power Scaling, which is a technique to adjust the internal regulator output voltage to further reduce power consumption provided by the integrated Backup Power Manager Module. In addition, the SAM4L series comes with two regulator options to supply system power based on the application requirement. While the buck/switching regulator delivers much higher efficiency and is operational from 2 to 3.6V. The linear regulator has higher noise immunity and operates from 1.68 to 3.6V.

The Atmel® SAM4L ARM® Cortex®-M4 based Microcontroller

The Atmel® SAM4L ARM® Cortex®-M4 based Microcontroller

It’s all about system intelligence and conserving energy. Simply put, the SAM4L microcontroller is your choice if you are designing a product that requires long battery life but you don’t want to sacrifice performance.  To get started, learn more about Atmel SAM4L Xplained Pro Evaluation and Starter Kits.