Welcome to the Biosignal Revolution
Suppose you could measure your mood, your stress level, or enthusiasm electronically and use it to control your surroundings? I have been using the original BITalino board for a couple years — an Arduino-like microcontroller dev board with built-in biosignal sensing modules — in projects such as mood-controlled inflatable wearables (build yours here). The new version of the board, the BITalino (r)evolution, is a welcome upgrade in sensing power and connectivity.
The maker-friendly cardboard packaging doubles as a project enclosure; helpful drawings on the side invite you to cut the box to fit your needs. Inside you’ll find the BITalino circuit board, a 5-step quick-start instruction, LiPo battery, electrode pads (5), and two cables.
The distinctive white BITalino board has a breakaway structure similar to the ProtoSnap by SparkFun or the WunderBar system. You can test your board as is, out of the box, but as soon as you’re ready to build it into your gadget or application, you can simply snap off the modules you need (or don’t need).
The new board design is equal in size to the previous version, however the designers managed to pack in more functionality. Besides modules for measuring EDA (skin conductance), ECG (heart signals), and EMG (muscle signals) already found in the previous model, a new amplifier for EEG (brain waves) is added! And in addition to the previously available LED, lux (light) sensor, and accelerometer, they’ve also added a buzzer, button (user input), analog output (DAC), and prototyping area. And the board is now available in both Bluetooth Classic and Bluetooth Low Energy (BLE) versions.
Where the previous edition used a Molex Sherlock connector, the new (r)evolution board has been made future-proof by choosing 8-pin UC-E6 connectors that resemble mini-USB plugs. These are used to connect electrodes to the sensor amplifiers, but can also be used to connect the sensor amplifiers to the main board (if you’d like to rearrange or separate them).
In order to maintain galvanic isolation at all times (so the wearer won’t suffer stray shocks from any electronic gear) the board is powered by its own tiny LiPo cell and it communicates to the outside world using Bluetooth. Although the manufacturer explicitly claims the device is not intended for medical use, this design ensures operation at a much safer level than some of the other Arduino-based biosignal circuits out there. (Yes, those can be safe too — as long as you have your laptop running on battery.)
Speaking of Arduino, every bit of documentation regarding the board is available online. The heart of the BITalino is the ATmega328p microcontroller which also powers many Arduino-style boards. The firmware has been written using AVR-GCC but with a different set of libraries than standard Arduino. The sources are, however, available at the BITalino website and Github repository.
The BITalino site also offers SDKs or APIs for many different platforms. Their OpenSignals platform offers browser-based recording and viewing of data. Furthermore, support for almost every platform used in DIY or academia (Matlab, LabVIEW, Max, Python, Raspberry Pi, Arduino, Unity, Java, C#, C, Android) is offered. Also 3D printable models (STL files) for enclosures and belt clips, are available online. Respiration and temperature sensors are also sold separately.
The getting-started guide follows the usual five steps: unpack, plug in, download software, connect, and start working. The OpenSignals application is web-browser based and allows you to quickly monitor and record your biosignals. The BITalino website provides detailed instructions and datasheets on the sensors used, with helpful information about where to place electrodes and such.
Although Bluetooth connectivity can be flaky at times (nothing to do with the BITalino board, I guess that’s just Bluetooth for you) the setup goes really smoothly and allows you to admire your body signals in no time. You can immediately take advantage of the incredible amount of effort the makers (and users) of the project have put into documentation and support. The price tag ($20 for the microcontroller only; $103 for the all-in-one board with microcontroller, Bluetooth, charger, and 10 sensors and actuators; $167 for the starter kit) is very reasonable for the amount of technology, documentation, and the incredible possibilities waiting for you to unleash.
Going Further: Projects
As quick tests, I created two programs to run on the BITalino using Processing.org: a simple graphing function, and a BITalino Pong game — use your muscle tension to lift the paddle and smash that (terribly slow) ball back! Read both projects here on Make: