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.

5 thoughts on “Getting up close and personal with the IMUduino BTLE

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