A golf club grip assembly has an upper grip fixedly mounted to a hollow shaft of a golf club, and a substantially identical lower grip, interchangeably mountable with the upper grip, and rotatable relative to the upper grip and the shaft. Implementations of systems, methods and apparatus disclosed herein enable a USB compliant device to selectively process interrupts andor other overhead resulting from USB communications between a host and the device. However at the actual frequency offset, the signal phase is no longer uniformly distributed over \u2212\u03c0,\u03c0; in other words the signal phase will take some specific values in \u2212\u03c0,\u03c0, therefore a peak PMF sum-square value will result. Measuring circuitry is connected to the sensing element and the compensating element for determining gas pressure in the environment to which the sensing element and compensating element are exposed based on electrical response of the sensing element and the compensating element.