The disclosure provides a tire pressure sensor assembly that includes a battery and a printed circuit board (PCB) configured with electronics to measure tire pressure and to transmit an electromagnetic signal related to the measured tire pressure. The PCB and battery are contained in a housing that allows the PCB and the battery to be angularly oriented with respect to each other. Such orientation permits the sensor to conform to the curved surface of the rim. An embodiment of the disclosed tire pressure sensor assembly is adapted to fasten to a valve stem via a metal terminal. The attachment configuration permits the valve stem assembly to deform as the valve stem is installed in a rim and also allows the valve stem to function as a portion of the antenna structure to facilitate transmitting the RF signal to a receiver.