Abstract: A pen apparatus with a pressure sensitive tip mechanism that internally generates pressure, tilt, and/or barrel rotation through the use of a multi-axis measurement scheme with simultaneous transmit, receive, and sensing driver capability operable in conjunction with a receiving system or in a relative stand-alone manner. Signaling schemes are provided for operating the pen apparatus to achieve improved function. Systems and methods are provided for operating a pen, and for operating a pen with a touch sensor system. Drive/receive circuitry and methods of driving and receiving sensor electrode signals are provided that allow digital I/O pins to be used to interface with touch sensor electrodes. This circuitry may be operated in modes to sense various combinations of signals coupled within a pen, or from outside of a pen.

Abstract: Circuitry, systems, and methods are provided that can acquire touch sensor data simultaneously for different modes of, for example, self, mutual, and pen, and with simultaneous sampling of the different channels. Drive/receive circuitry and methods of driving and receiving sensor electrode signals are provided that allow digital I/O pins to be used to interface with touch sensor electrodes using external passive filter components. Drive/receive circuitry is provided employing voltage following sigma-delta A/D coverts that are adapted to both drive and sense touch sensor signals on multiple frequencies simultaneously. This circuitry may be operated in modes to sense various combinations of mutual, self, and pen touch signals simultaneously. While capacitive multi-touch sensors are preferred, the circuits and methods herein are useful with many other types of touch sensors as well.