Tag Archives: Cortex- M0+ core

Arduino Zero takes center stage at Maker Faire

Arduino and Atmel recently debuted the Zero, a 32-bit development board powered by Atmel’s ARM-based (Cortex M0+ core) SAMD21 microcontroller (MCU).

Today, the Zero took center stage at Maker Faire Bay Area, as Arduino co-founder Massimo Banzi, along with ARM and Atmel execs, unveiled the long-awaited board for all to see.

As we’ve previously discussed on Bits & Pieces, the Zero features 256kb of flash, 32kb SRAM in a TQFP package and compatibility with 3.3V shields that conform to the Arduino R3 layout.

In addition, the Arduino Zero board boasts flexible peripherals along with Atmel’s Embedded Debugger (EDBG) – facilitating a full debug interface on the SAMD21 without the need for supplemental hardware.

Last, but certainly not least, EDBG supports a virtual COM port that can be used for device programming and traditional Arduino bootloader functionality.

Interested in learning more about the Atmel-powered Arduino Zero? You can check out the dev board’s official page here.

FreeMotion Library selected for Atmel’s SAM D20

Atmel has selected Sensor Platforms’ FreeMotion Library as part of a rapidly growing ecosystem to support its low power, high-performance flexible SAM D20 Cortex M0+ core.

As we’ve previously discussed on Bits & Pieces, the ARM-based SAM D20 core is specifically tailored for sensor hubs and sensor-focused software. Its optimized features and flexible development ecosystem allow Atmel customers to create unique and differentiating products incorporating always-on sensors.

“As sensors increasingly find their way into all kinds of mobile devices, wearables and IoT (Internet of Things) applications, there is a huge premium on providing always-on functionality at a tiny fraction of system power – and we found this in the FreeMotion Library from Sensor Platforms,” said Dr. Reza Kazerounian, Sr. VP and GM, Microcontroller Business Unit, Atmel Corporation. “Software from our partners is available now and compatible with our own development environments.”

Dan Brown, CEO of Sensor Platforms, expressed similar sentiments and noted that the company’s low-power solution offers best-in-class capabilities to optimize power consumption, thereby enabling longer battery life.

“[Our] FreeMotion Library makes sensor fusion and user context awareness available in smartphones and tablets, in order to: combine and process data from installed sensors and microprocessors; better interpret users’ movements and situations; and infer users’ intents,” Brown explained.

“The library makes it easy for device OEMs to purchase their sensors and microprocessors from multiple suppliers without damaging user experience. It also automatically optimizes sensor and platform power consumption based on user movement and contexts to enable longer battery life.”

FreeRTOS with Atmel’s SAM D20 Xplained Pro

Atmel’s SAM D20 lineup is based on the ARM Cortex- M0+ core, setting a new benchmark for flexibility and ease-of-use. The microcontroller (MCU) series is ideal for a number of low-power, cost-sensitive industrial and consumer devices, such as GPS trackers, appliance controllers, intelligent remotes and optical transceivers.

As William Wong of Electronic Design notes, the SAM D20 specifically targets the entire low-end space currently handled by 8- and 16-bit microcontrollers, while also hitting the low-end 32-bit space.

“The SAM D20 incorporates high-end support like the high-speed bus matrix linked to three AHB/APB bridges. System and power controllers can be found off one bridge. Memory controllers are found off another,” Wong wrote in an article posted on Electronic Design earlier this year. “The third bridge handles the convention interfaces that include up to six programmable serial ports, eight timers, a 20-channel, 350-ksample/s analog-to-digital converter (ADC), a pair of comparators, and a 10-bit, 350-ksample/s digital-to-analog converter (DAC). There is also Atmel’s touch interface controller.”

Recently, a detailed SAM D20 demo project went live on FreeRTOS.org (FreeRTOS, FreeRTOS+CLI).  The demo – which targets Atmel’s SAM D20 Xplained Pro evaluation board – leverages the FreeRTOS ARM Cortex-M0 GCC port and builds with the free Atmel Studio IDE (using the Visual Studio framework and kernel aware FreeRTOS plug-in).

Meanwhile, the command line interface character input and output employs drivers provided Atmel’s Software Framework (ASF), with a #define tasked with switching the build between a simple blinky style application and a comprehensive test/demo application that incorporates the FreeRTOS+CLI component.

Want to build and run the ARM Cortex-M0+ RTOS Application? It should probably be noted that the FreeRTOS download contains the source code for all FreeRTOS ports, so obviously there is a surplus of unneeded files for this specific SAMD20 demo. As such, it might be a good idea to check out the the Source Code Organization section for a description of the directory structure. The Atmel Studio solution file is called RTOSDemo.atsln, which is located in the FreeRTOS/Demo/CORTEX_M0+_Atmel_SAMD20_XPlained directory.

Building and running the ARM Cortex-M0+ RTOS application

  1. Open FreeRTOS/Demo/CORTEX_M0+_Atmel_SAMD20_XPlained/RTOSDemo.atsln in the Atmel Studio IDE.
  2. Locate the mainCREATE_SIMPLE_BLINKY_DEMO_ONLY definition at the top of main.c.
  3. Set mainCREATE_SIMPLE_BLINKY_DEMO_ONLY to 1 to create the simple blinky demo, or 0 to create the comprehensive demo that also includes the command line interpreter.
  4. Select “Rebuild RTOSDemo” from the Atmel Studio “Build” menu (or press F7) to build the demo project.
  5. Connect a USB cable between the USB port on the SAMD20 Xplained Pro board and the host computer.
  6. Select “Start Debugging and Break” from the Atmel Studio “Debug” menu to program the microcontroller flash memory and kick off a debug session.

Interested in learning more about running FreeRTOS on Atmel’s SAM D20 Xplained Pro? Be sure to check out the official FreeRTOS demo here.

A closer look at Atmel’s SAM D20 Xplained Pro eval kit

Atmel’s SAM D20 lineup is based on the ARM Cortex- M0+ core, setting a new benchmark for flexibility and ease-of-use. The recently launched MCU series is ideal for a number of low-power, cost-sensitive industrial and consumer devices, such as GPS trackers, appliance controllers, intelligent remotes and optical transceivers.

Perhaps most importantly, the SAM D20 also offers engineers easy access to an expansive array of software and hardware tools, including Atmel Studio 6 (free IDE with compiler) as well as the SAM D20 Xplained Pro evaluation kit.

The $39  kit supports the Atmel I/O1 Xplained Pro, OLED1 Xplained Pro and PROTO1 Xplained Pro extension boards, all of which can be purchased individually.


In terms of key specs, the board is powered by a SAMD20J18 microcontroller and features one mechanical reset button, a single mechanical user pushbutton (wake-up, bootloader entry or general purpose), a yellow user LED, 32.768kHz crystal and three Xplained Pro extension headers.

Additional specs include an embedded debugger, Auto-ID for board identification in Atmel Studio 6.1, one yellow status LED, one green board power LED, Data Gateway Interface (SPI, I²C, 4 GPIOs) and a virtual COM port (CDC).

Atmel’s SAM D20 Xplained Pro evaluation kit can be purchased here for $39.