Another on of my posture monitor projects again involves an Attiny85. While my previous sensors were either fixed to a chair or desk, this time I wanted to create a wearable version, that would allow for free movement. An ADXL335 is used to measure the angle of the chest to determine the posture. A vibrating motor gives haptic feedback if the posture is bad. All the parts including a coin cell to power the electronics fit into a custom 3D printed case.

http://coretechrobotics.blogspot.de/2016/03/a-diy-wearable-posture-sensor.html