A system includes sensing modules positioned along a length of a drill string. Each sensing module includes a structure arrangement composed of an outer structure body having a cavity and an inner structure body rotatably supported within the cavity. The structure arrangement is coupled to the drill string such that rotation of the drill string produces a relative rotation between the structure bodies. Ball elements are disposed in a gap between the structure bodies and move along a predetermined path defined in the gap in response to relative rotation between the structure bodies. Movable elements are positioned to physically interact with the ball elements as the ball elements move along the predetermined path. Energy harvesters in the sensor modules generate electrical energy from the mechanical energy produced by physical interaction between the ball elements and movable elements. The sensing modules include sensors to measure parameters in the drill string environment.