What is it?

This is a Wireless IMU platform. Think of it like an electric cochlea. Self balancing robots, motion processing, and more!

It is Arduino compatible, and includes the following:

• Five (5) FemtoBeacon coins, r2.0.7 (with u.FL connector option included, USB Host capabilities, and RGB LED)
• One (1) FemtoBeacon RF Dongle r2.0.6 (with u.FL connector option included, and RGB LED)
• Arduino examples
• One (1) hour of help/support via Google Hangouts is included!

We recommend the USB OTG cable and Adapter. The coin has USB OTG support! The cable and adapter also allows you to power your device off a USB Charger battery, and read a Micro SD card!

The FemtoBeacon coin, RF dongle, and code are 100% Open-Source. We are continually adding new examples, including support for VR integration (Unity3D, UE4). You can stream real-time wireless IMU and RF data to any machine.

Here are some features on this tiny beast

• 100% Arduino compatible. Sketch upload via USB, or Atmel ICE programmer.
• Accepts up to 5.5V via USB Port, or VIN pin. Outputs 3.3V on 3V3 line.
• Integrated High Speed USB
• Runs at 48MHz. The chipset is ATMEL SAM R21E (ATSAMR21E18A), is Arduino compatible.
• Coin: Precision Altimeter (MS561101-BA03) on I2C. See datasheet.
• Coin: 9 Axis IMU (MPU-9250) on I2C. See datasheet.
• Coin: Works with the latest FreeIMU library updates (from the femtoduino/FreeIMU-Updates repository!)
• 2.4 GHz RF, and can be programmed to use any available 2.4 GHz RF stack (we use LwMesh)
• Can also generate an internal 96MHz Fractional Digital Phased Locked Loop (FDPLL)!
• Can be configured to provide an internal RTC. Supports sleep/wake!

Chip Specs (ATMEL ATSAMR21E18A)

• ARM Cortex M0+ at 48MHz, can be configured to provide an internal 96MHz Fractional Digital Phased Locked Loop clock source.
• Single-cycle hardware multiplier
• Micro Trace Buffer (MTB)
• 256KB in-system self-programmable flash.
• 32KB SRAM
• Power-on reset (POR) and brown-out detection (BOD)
• Idle and standby sleep modes
• Sleepwalking peripherals
• See data sheet

Note, get an Atmel ICE programmer to re-burn a bootloader should the board become "bricked". See https://www.kickstarter.com/projects/1265095814/the-dime-sized-femtobeacon-wireless-imu-arm-cortex/posts/1669637

Voltage

• Input voltage 5.5V max (via USB or VIN pin only!). Outputs 3.3V on the 3V3 line.
• Operating voltage is 1.8V - 3.6V, can be supplied via 3V3 line.

Dimensions

• FemtoBeacon Coin is ~18mm in diameter (plus part of USB port, and antenna area on one side).
• FemtoBeacon RF Dongle connects to a standard USB 2.0 port (on your computer, or to a USB battery charger)

Pinout

• up to two (2) I2C sets of pins.
• INT (Interrupt pin)
• FS (FSYNC pin)
• USB+ and USB- pins broken out.
• SWD pins
• Up to four (4) GPIO digital pins.
• In progress. Stay tuned!
• Data may be read/written via SerialUSB in your Arduino sketch!

Arduino Core and Bootloader, libraries

• Arduino core, bootloader, examples for SAM D21E, SAM R21E
• FreeIMU-Updates library, see FreeIMU.h for config!
• Arduino port of LwMesh as a library, at86rf233 support branch
• Femtoduino fork of RTCZero library, osculp32k branch
• Arduino driver of internal AT86RF233 radio module

Hardware schematic and board design

• EAGLE PCB schematic and board, develop branch

Why did you make it?

We are incredibly grateful for all of the FreeIMU community's hard work. We wanted to give back to the open source FreeIMU community by providing a 100% Open Source platform that would replace the original FreeIMU board. We hope it proves useful in the fields of physical computing, wearables, and robotics.

Our design is provided as an EAGLE PCB schematic and board (4-layer). It uses 0201 components (two sided), but is still something you can assemble by hand.

What makes it special?

It is the smallest wireless (open source!) IMU in the world! Not even the Curie module is a match for this design. Our design is 100% open source, 100% Arduino compatible, and AWESOME for projects where precision, weight and size are critical.