This is a brief preview of Notch Android SDK. The SDK will be available as a library that manages the communication and data transfer between the Notch devices and the phone/tablet, processes the measurements and provides 3D visualiser for the recorded motion.


Notch Device

Notch Devices (notches) are the physical layer of the system, actual devices that capture motion and deliver data to the host (mobile) application. Each module has a unique MAC address, a Network ID and Name.

Device Connectivity

Notch Device will initiate connection when turned on. Notches use Bluetooth 4.0 protocol for communication.


Bone is a vector that has mandatory Name (e.g. “RightUpperArm”) and length (e.g. 0.3m) parameter. Extra bones can be added to represent for example an equipment.


Skeleton is a biomechanical model of the human. It is a tree-structured hierarchy of bones originated from single root bone. The following figure illustrates the hierarchy of the default Notch Skeleton composed of 19 bones:



Workout is the measurement setting for tracking pre-set motion or group of motions (e.g. baseball swing, punching drill, shoulder mobility test). Workout is the core element of Notch-compatible app architecture. New Workout always starts with a steady Measurement and us followed by a series of regular Measurements.


Measurement is the motion data collected from Notch devices that is used for visualization, processing and setup. This document refers to two types of Measurements - Steady and Regular.

Steady measurement is the data collected during the Steady phase. Steady phase is a brief sensor alignment procedure user must perform at the very beginning of the recording session. During steady phase user must stand with the arms straightened and legs shoulder-width for about 2 seconds. Once steady phase is complete user can perform as many recordings as necessary until they remove or move Notch sensors.

Regular measurement is the data collected during any other recording.