A self-powered tire revolution counter includes a motion sensitive power
generation mechanism, a power conditioner, a pulse detector, a
microcontroller, and, optionally, a radio frequency (RF) transmitting
device. In one exemplary embodiment, the power generation mechanism
corresponds to a piezoelectric patch that, during movement, provides both
operating electrical power and pulsed signals indicative of tire
rotation. The power conditioner receives a generator signal from the
power generation mechanism and produces a conditioned output voltage that
can be used to power associated electronic devices, including the
microcontroller. The pulse detector receives the generator signal and
produces a detection signal whenever the generator signal meets a
predetermined condition. The microcontroller is programmed to determine
current and lifetime-accumulated values of selected pulse indications in
the detection signal that meet predetermined criteria. Data corresponding
to tire environment related parameters such as temperature, pressure,
tire deflection, and/or vehicle speed may be stored in the
microcontroller at times during tire rotation as power is supplied from
the power generation mechanism through the power conditioner. Additional
data may be supplied to the microcontroller directly from an external
source and read from the microcontroller either by direct electrical
contact or via selective RF transmission.