Tag Archives: Femtoduino

FemtoBeacon is a dime-sized, open-source wireless IMU

Based on an ARM Cortex-M0+ MCU, this board features an altimeter, a 9-DOF IMU and wireless capabilities.

In recent months, the Femtoduino crew has been hard at work developing a range of new boards, including their highly-popular IMUduino BTLE, and even more recently, the uber-mini FemtoUSB. Now, after much anticipation, the crew has returned with a dime-sized FemtoBeacon.


Currently live on Kickstarter, the tiny board (only 18mm in diameter) is based on an Atmel | SMART SAM R21 Cortex-M0+ MCU and is packed with a 9-DOF IMU, a temperature sensor, an altimeter and integrated wireless capabilities such as ZigBee and mesh networking.


Built around the ARM Cortex M0+, the FemtoBeacon features 256KB of Flash and an on-board voltage regulator outputting 3.3V. At the moment, the device uses a 26MHz crystal with 9PF caps, but it should be noted that the SAM D21 is capable of going up to 48MHz. The chip also supports uploading programming over USB, thanks to the SAM-BA bootloader, and the FemtoIO fork of the BOSSA utility. The entire flash storage may be used if programmed with the Atmel-ICE dongle via SWD.


“Hopefully, this small Kickstarter campaign can raise enough money to get a small batch built, and subsequently have libraries developed,” CTO Alex Albino writes. Ideally, with enough funding, the team is looking to extensively upgrade its wireless IMU and programming capabilities, as well as add other features like Arduino compatibility.

Intrigued? Head over to the FemtoBeacon’s Kickstarter page, where Femtoduino is seeking $500. Shipment is slated to begin July 2015. In the meantime, you can follow along with their latest work, libraries and examples on Github here.

25 dev boards to help you get started on your next IoT project

A closer look at some of today’s most popular development boards to help you get started on your next IoT design.

With billions of everyday objects expected to become Internet-enabled over the next couple of years, Makers are continually seeking new ways to add connectivity to their designs. As a result, hobbyists and engineers are turning to a wide range of IoT development boards and platforms to better accelerate and ease the process.

Being at the heart of the IoT and all, we’ve decided to compile a list of just some of today’s most popular, Atmel powered ones that will surely help as you embark on your next prototype or project. (Keep in mind, there are countless others, with new ones popping up on the daily!)

SAM R21 Xplained Pro


The Atmel | SMART SAM R21 Xplained Pro is a hardware platform to evaluate the ATSAMR21G18A microcontroller. Supported by the Atmel Studio integrated development platform, the kit provides easy access to the features of the Atmel ATSAMR21G18A and explains how to integrate the device in a custom design. The Xplained Pro MCU series evaluation kits include an on-board Embedded Debugger, and no external tools are necessary to program or debug the ATSAMR21G18A. A great option for those developing an 802.15.4/ZigBee design.

Arduino Uno


The Arduino Uno R3 is a microcontroller board based on the ATmega328. It has 14 digital input/output pins (of which six can be used as PWM outputs), six analog inputs, a 16 MHz crystal oscillator, a USB connection, a power jack, an ICSP header, and a reset button. Simply connect it to a computer via a USB cable or power it with a AC-to-DC adapter or battery to get started.

Arduino Yún


The Arduino Yún is a microcontroller board based on the ATmega32U4 and the Atheros AR9331. The board comes with built-in Ethernet and Wi-Fi support, along with a USB-A port, microSD card slot, 20 digital input/output pins (of which seven can be used as PWM outputs and 12 as analog inputs), a 16 MHz crystal oscillator, a micro USB connection, an ICSP header, and three reset buttons. What’s more, Facebook’s Parse recently unveiled a new line of SDKs for connected devices with the first Arduino SDK targeted for the Yún.

Arduino Pro Mini


Intended for semi-permanent installation in connected objects, the Arduino Pro Mini is based on the ATmega328. The board boasts 14 digital input/output pins (of which six can be used as PWM outputs), six analog inputs, an on-board resonator, a reset button, and holes for mounting pin headers. A six-pin header can be connected to an FTDI cable or Sparkfun breakout board to provide USB power and communications.

Arduino Nano


The Arduino Nano is a small, breadboard-friendly board based on the ATmega328. The microcontroller has more or less the same functionality of the Arduino Duemilanove, but in a different package. It lacks a DC power jack, and works with a Mini-B USB cable instead of a standard one.



With an Atmel ATmega256RFR2 at its core, Pinoccio is a wireless, web-ready MCU packed with Wi-Fi, LiPo battery and a built-in radio. Each unit can communicate with one another using a mesh network, making them 14 times more efficient than standard Wi-Fi devices.



The TinyCircuits TinyDuino is an Arduino-compatible, ATmega328P based board in an ultra-compact package that provides Makers with the full power of an Uno in a size that’s less than a quarter.



UDOO is a multi-development platform solution for Android, Linux, Arduino and Google ADK 2012. The board, which is built upon an ARM Cortex-A9 CPU and Atmel | SMART SAM3X8E ARM Cortex-M3 CPU, is designed to provide a flexible environment that lets Makers explore the new frontiers of the Internet of Things and switch between Linux and Android in a matter of seconds, simply by replacing the MicroSD card and rebooting the system.

Libelium Waspmote


Waspmote is an open-source, ATmega1281 based wireless sensor platform specially focused on the implementation of low consumption modes to enable the sensor nodes to be completely autonomous and battery powered, offering a variable lifetime between one and five years depending on the duty cycle and the radio used.

The AirBoard


The AirBoard is a thumb-sized, all-in-one MCU designed for ultra-fast prototyping on IoT projects. The open-source board is equipped with an ATmega328P and pre-loaded with the standard Arduino Fio bootloader. The wireless-friendly computer supports automatic over-the-air programming via Bluetooth, Wi-Fi or XBee, and can be controlled by smartphone or the web.

Tessel 2


Tessel 2 is an affordable, accessible and robust development platform that lets Makers build connected hardware devices. The board packs built-in Wi-Fi, an Ethernet jack, a pair of USB ports, and a system that runs real Node.js/io.js. Meanwhile, it employs a processor/coprocessor architecture, combining an Atmel | SMART SAM D21 Cortex M0+ MCU to control I/O and a Mediatek MT7260n Wi-Fi router SoC to run user code, host USB devices and handle the network connections.



panStamps are small wireless modules programmable within the Arduino IDE. Each module contains an Atmega328P MCU and an RF interface, providing the necessary connectivity and processing power to create autonomous low-power wireless motes.



Flutter is a $36 wireless Arduino with a half-mile range that lets users develop mesh networking protocols and connected devices in an efficient yet inexpensive manner. It’s perfect for robotics, consumer electronics, wireless sensor networks, and educational platforms. Flutter is packed with a powerful Atmel | SMART SAM3S Cortex-M3 processor, while an ATSHA204 crypto engine keeps it protected from digital intruders.



SODAQ is a LEGO-like rapid prototyping board driven by an ATmega328P that gives Makers and engineers the ability to easily connect a wide variety of sensors and devices to the Internet efficiently. With its solar powered data acquisition technology, data can be collected virtually anywhere and seamlessly transferred to the web.



Billed as the smallest Arduino Leonardo compatible clone, the IMUduino includes an ATmega32U4 at its core, as well as USB keyboard/mouse emulation, on-board Bluetooth LE, real-time orientation and motion sensing IMU, as well as a 10V max voltage regulator.

SparkFun RedBoard


The SparkFun RedBoard combines the simplicity of the Arduino Uno’s Optiboot bootloader, the stability of the FTDI and the R3 shield compatibility of the latest Arduino Uno. The ATmega328 based board can be programmed over a USB Mini-B cable using the Arduino IDE.



The XinoRF is an Arduino-compatible electronics development board with an onboard 2-way Ciseco SRF data radio, which supports over-the-air programming, features built-in wireless capabilities and is powered by an ATmega328P.

The Rascal


The Rascal is a small, AT91SAM9G20 powered computer that Makers can use to monitor and control their connected world remotely. In addition, it features its own web-based editor on-board, is compatible with most Arduino shields, and can be programmed in Python.



Microduino is a quarter-sized Arduino-like board with an ATmega328P at its heart. With a unique UPin-27 pinout, Microduino’s plug-and-play modules can be easily stacked together to add functionalities.



Nanode is an open-source, Arduino-like board that is equipped with built-in Internet connectivity and based on an ATmega328P. The low-cost, upgradeable board is ideal for those looking to bring their IoT ideas to life.

OpenKontrol Gateway


The OpenKontrol Gateway is an ATmega328 driven kit that enables communication between many common mediums and protocols. It is totally compatable with the Arduino IDE and supports Wi-Fi, low-power RF, Ethernet and Bluetooth. Beyond that, it can be configured with on-board SRAM, an SD card, a real-time clock, and a coin-cell battery and sports an FTDI programming port.

Arietta G25


Arietta G25 is an uber-mini system-on-module powered by a SAM9G25 ARM9 processor. The 20mm x 50mm board, which was developed with the Maker community in mind, is ideal for low-power, embedded gadgets and other DIY IoT devices.



WIOT is an open-source, rechargeable development board for the Internet of Things built around the ATmega32U4. WIOT also boasts integrated Wi-Fi capabilities through an on-board ESP8266 module.



SmartEverything is a dev board equipped with sensor options, communication interfaces and connection to the cloud for IoT designs. An Atmel | SMART ARM Cortex-M0+ based CPU USB host orchestrator chip manages traffic between peripherals, while an Atmel CryptoAuthentication device (ATSHA204) enables the implementation of a full security SHA-256 hash algorithm with message authentication code. The board utilizes the SIGFOX global network cellular connectivity solution to enable access to the IoT.



Apio is an open-source IoT platform, which lets Makers and designers create their own smart systems and connected objects in a matter of minutes. It is comprised of two USB devices, the General and Dongle, both of which are based on an ATmega256RFR2 and ATmega16U2, along with a custom operating system and SDK.

LightBlue Bean


The LightBlue Bean is a Bluetooth Low Energy, Arduino-compatible microcontroller. Using Bluetooth 4.0, it is wirelessly programmed, runs on a coin cell battery and is perfect for smartphone-controlled projects. Powered by an ATmega328P, the board features a three-axis accelerometer, a temperature sensor, an RGB LED, and includes iOS, OS X and Windows 8 support.

FemtoUSB is an open-source Cortex-M0+ board

The latest board from Femtoduino is designed to help those looking to migrate from AVR to ARM-based designs.

You may recall Femtoduino from their recent campaign around the highly-popular IMUduino BTLE. Now, the crew is back with their latest device, an uber-mini Cortex-M0+ MCU that they call FemtoUSB. The board was designed as a basic starting point for those interested in ARM-based projects, particularly for those transitioning from 8-bit AVR.

“Before the release of the FemtoUSB, learning to design for ARM chips was very difficult,” the team writes. “Compiling a toolchain? What does the most basic schematic for an ARM chip even look like? What in the world is JTAG?”


Recently launched on Tindie, FemtoUSB is built around an Atmel | SMART ATSAMD21E18A, featuring 256KB of Flash and up to a 48MHz operating frequency. Its creators note that its schematic follows the suggested design found in the SAM D21 data sheet. The device features 3.3V on-board regulator (VIN line), a supply up to 10V, and a regulated down to 3.3V on the 3V3 line. The FemtoUSB comes with a standard 0.1″ (2.54mm) pin spacing design for breadboards, and a smaller 0.05″ (1.27mm) pin spacing design for tinier projects.

“Atmel has some of the best support for the open-source hardware community. They offer proper documentation, excellent chip performance, and a great foundation via the Atmel Software Framework,” Alex Albino, Femtoduino Senior Engineer, explains. “Did we mention how easy it is to get started with ARM using Atmel?”


Migrating from 8- to 32-bit is much easier today than it was in years prior. As the Femtoduino team points out, most microcontrollers have a similar set of requirements, which range from adding some resistors and a reset circuit to hooking up a USB port and burning a bootloader.

“You can of course, add in a reverse current protection circuit, a crystal clock source for chips that don’t have an internal one (or if you want a faster clock source), some fancy peripheral additions, etc. However, here’s where we will draw an imaginary line, and now distinguish between 8-bit AVRs and 16/32-bit ARM chips.”

When working with ARM chips, Albino advises that you will need a programmer dongle to initially burn a bootloader. Serial Wire Debug seems to be the most basic form of the JTAG interface — something provided by all ARM chips. This is akin to the “Ardiuno ISP” mode of programming. Keep in mind, though, not all chips “talk the same” between the chip and a dongle.


“It’s kind of like how two people can have the same interface (vocal chords), but speak different languages. Fortunately, it seems Atmel’s SAM D21 chips talk Cortex Microcontroller Software Interface Standard (CMSIS), which is a vendor-independent hardware abstraction layer for the Cortex-M processor series. This is another great reason to use Atmel’s line of ARM chips, for what it’s worth.”

The pins used to provide a JTAG connection vary depending on the ARM chip selected, and offer more debugging features when more pins are added. For the most part, JTAG Serial Wire Debug establishes the five necessary connections: Ground, Voltage Reference, Reset, Serial Wire Clock (SWCLK), and Serial Wire Debug Input/Output (SWDIO).


Albino shares that your programming dongle should have a datasheet informing you of the pinout provided, which will enable you to wire it to your board accordingly. Another key difference — and a very important one for that matter — is the voltage. You may be used to 5V logic levels working with AVR 8-bit chips, but 5V can be utterly destructive to an ARM chip as they are meant to work with less power. The usual voltage range for Atmel’s line of ARM chips is somewhere between 1.8V to 3.3V.

“As with all ARM chips, you will benefit greatly from having a programmer dongle. Some vendors lock their chips behind really expensive software tools, and even more expensive programmer dongles ($200+). Oh, and have fun trying to get their proprietary stuff working with your open source setup. Thankfully, Atmel offers their ATMEL-ICE programmer at a reasonable price of about $85. I hear you can get them much cheaper without the case, though don’t expect it to come with ribbon cables if you go the cheap route.”


Bringing the FemtoUSB to life required the following components:

Additionally, the project calls for some low-temp lead-free solder paste, a couple PCBs and SMD components. On the software side, the team suggests using Atmel Studio with Windows or Terry Guo’s GNU ARM Embedded Toolchain for those running Mac OS X or Linux.


Regardless the operating machine, Albino stresses that Atmel Software Framework and Atmel SAM-BA In-System Programmer are required. The board also comes pre-loaded with the AT07175: SAM-BA Bootloader for SAM D21, “which is what actually gets programmed on to the chip so we can load stuff via USB instead, thanks to the open-source BOSSA utility.” (Hence, the name FemtoUSB.)

Femtoduino does reveal that they are working on getting an Arduino integration working, along with other non-Arduino tools to load things via USB. Interested? Femtoduino is now available on Tindie for $24.99. Those wishing to learn more can also head over to the project’s Github page here.

Getting up close and personal with the IMUduino BTLE

Makers, though Arduino-compatible boards seem to be a dime a dozen these days, this one is different. It’s very different. The innovators over at Femtoduino have developed an uber-tiny device for all of your emulation needs, the IMUduino BTLE. Given its extremely small form factor, development on this board is ideally suited for development and hardware accelerating/prototyping of wearables, smart watches, rockets, and other embedded systems.


Recently launched on Kickstarter, the Atmel based Arduino-compatible board comes in at just under 2.7 grams and is packed with USB keyboard and mouse emulation, Bluetooth LE (BLE), real-time orientation and motion sensing IMU, as well as 10V max voltage regulation. What more can you ask for in such a mini machine?


The IMUduino has the ability to transmit IMU data over BLE, making it a perfect companion for any project that involves wireless motion. Femtoduino notes that the board can be utilized in a variety of projects, or anything that requires connectivity for that matter, using the ultra low power sipping Bluetooth LE.


Femtoduino’s latest device is capable of working with a reduced version of the FreeIMU library, as well as the Adafruit nRF8001 library. Furthermore, the IMUduino is the smallest Arduino Leonardo clone possessing the same power and pin count as the original, thanks to its onboard ATmega32u4.

Even with all of these features, the board still runs at a zippy 16 MHz with only 3.3V.

Ket specifications include:

  • 9/10 DoM/DoF motion and orientation IMU sensors
  • Same power and pin count of an Arduino Leonardo (USB keyboard/mouse emulation)
  • Small footprint at 2.7 grams
  • Nordic nRF8001 Bluetooth Low Energy using Adafruit’s nRF library
  • Width: 20.7 mm (0.81 inches)
  • Height: 15.2 mm (0.6 inches)
  • Pin spacing: 0.05 inch (1.27 mm) pitch
  • Weight: 2 grams (approx.)
  • VCC – Unregulated! 5V MAX
  • Operating Voltage: 3.3V to 5V
  • Amperage: VCC, VIN, GND – Do not exceed 200 mA. Amperage: All other pins – Do not exceed 40mA
  • VIN – Connects voltage though on-board voltage regulator. (10V max, converts to 5V)

Main chipset and sensors:

  • Microcontroller: Atmel ATmega32u4
  • InvenSense MPU6050 Six-Axis (Gyro/Accelerometer)
  • Measurement Specialties MS561101BA03-50 Barometer/Altimeter Sensor (High resolution mode, 10cm)
  • Honeywell HMC5883L 3-Axis Digital Compass IC

Dimensions, profile and power:

  • Width: 39.8 mm
  • Height: 15.72 mm
  • Pin spacing: 0.05 inch (1.27 mm) pitch
  • Weight: 2.7 gram(s)
  • 3.3V Logic and operating voltage.
  • 10V (400mA) MAX on the VIN (voltage regulated) line. Reduces to 3V3.
  • 3.6V MAX on the VIN line

PINS available:

  • I2C: Use D2 (SDA) and D3 (SCL)
  • SPI: D16 (MOSI), D15 (SCK), D14 (MISO). D17 is Slave Select (SS).
    Connect D10 or “reset” line of master Arduino to RST pin of your FemtoduinoBLE to upload bootloader via ArduinoISP sketch.
  • D16 to BLE MOSI
  • D15 to BLE SCK
  • D14 to BLE MISO
  • D10 to BLE REQN
  • D9 to BLE RST
  • D7 to BLE RDYN

With the inclusion of the onboard IMU, the IMUduino has the ability to provide real-time data at a highly impressive rate for such a small apparatus. The video above shows a simple wireless orientation test on one of the early iterations of the device.


In all, the IMUduino BTLE proves that big things can truly come in small packages. The limited size of Femtoduino’s device allows for an endless possibility of applications involving wireless orientation and real-time data. This board is intended for the Arduino IDE ecosystem and community of developers, and is completely Arduino IDE friendly. To get started quickly, you can add the Adafruit nRF library into your Arduino IDE’s library/folder. The IMUduino library is simply a lean and reduced version of the FreeIMU library. First things first, one can jumpstart early with a development board already packed with connectivity using IMUduino Bluetooth. Just follow their example IMU steps featured on their site.

Interested in learning more? Read all about the IMUduino BTLE on its official Kickstarter page here.