Abstract: In one embodiment, a stylus receives a first signal from a first electrode of the stylus, the stylus being operable to communicate wirelessly with a device through a touch sensor of the device; receives a second signal from a second electrode of the stylus, the second signal being a reference signal and the second electrode being a reference electrode; and compares the first signal with the second signal.

Abstract: In one embodiment, a stylus receives a first signal from a first electrode of the stylus, the stylus being operable to communicate wirelessly with a device through a touch sensor of the device; receives a second signal from a second electrode of the stylus, the second signal being a reference signal and the second electrode being a reference electrode; and compares the first signal with the second signal.

Abstract: In one embodiment, a stylus receives a first signal from a first electrode of the stylus, the stylus being operable to communicate wirelessly with a device through a touch sensor of the device; receives a second signal from a second electrode of the stylus, the second signal being a reference signal and the second electrode being a reference electrode; and compares the first signal with the second signal.

Abstract: In one embodiment, an active stylus includes a receiver and a transmitter configured to receive and transmit signals from and to a device via a touch sensor of the device, wherein the transmitter is integrated with or comprises an adaptive voltage generation circuit including: a boost voltage controller; a comparator; a switch control; and a bleeder circuit. The active stylus further includes a stylus controller configured to: (a) in a first operation state, control the adaptive voltage generation circuit and the transmitter to transmit signals at a second transmit voltage, and (b) in a second operation state different from the first operation state, control the adaptive voltage generation circuit and the transmitter to transmit signals at a first transmit voltage lower than the second transmit voltage.

Abstract: In one embodiment, a stylus receives a first signal from a first electrode of the stylus, the stylus being operable to communicate wirelessly with a device through a touch sensor of the device; receives a second signal from a second electrode of the stylus, the second signal being a reference signal and the second electrode being a reference electrode; and compares the first signal with the second signal.

Abstract: In one embodiment, an active stylus includes a receiver and a transmitter configured to receive and transmit signals from and to a device via a touch sensor of the device, wherein the transmitter is integrated with or comprises an adaptive voltage generation circuit including: a boost voltage controller; a comparator; a switch control; and a bleeder circuit. The active stylus further includes a stylus controller configured to: (a) in a first operation state, control the adaptive voltage generation circuit and the transmitter to transmit signals at a second transmit voltage, and (b) in a second operation state different from the first operation state, control the adaptive voltage generation circuit and the transmitter to transmit signals at a first transmit voltage lower than the second transmit voltage.

Abstract: In one embodiment, an active stylus includes a transmitter configured to transmit electrical signals to a device through a touch sensor of the device. The active stylus also includes a receiver configured to receive electrical signals from the device through the touch sensor of the device. Furthermore, the active stylus includes a controller configured to determine a strength of an electrical signal received by the receiver from the touch sensor of the device and instruct the transmitter to transmit electrical signals to the device at a voltage based at least on the determined strength of the electrical signal received by the receiver.

Abstract: In one embodiment, a stylus receives a first signal from a first electrode of the stylus, the stylus being operable to communicate wirelessly with a device through a touch sensor of the device; receives a second signal from a second electrode of the stylus, the second signal being a reference signal and the second electrode being a reference electrode; and compares the first signal with the second signal.

Abstract: In one embodiment, a stylus receives a first signal from a first electrode of the stylus, the stylus being operable to communicate wirelessly with a device through a touch sensor of the device; receives a second signal from a second electrode of the stylus, the second signal being a reference signal and the second electrode being a reference electrode; and compares the first signal with the second signal.

Abstract: In one embodiment, an active stylus includes a transmitter configured to transmit electrical signals to a device through a touch sensor of the device. The active stylus also includes a receiver configured to receive electrical signals from the device through the touch sensor of the device. Furthermore, the active stylus includes a controller configured to determine a strength of an electrical signal received by the receiver from the touch sensor of the device and instruct the transmitter to transmit electrical signals to the device at a voltage based at least on the determined strength of the electrical signal received by the receiver.

Abstract: In one embodiment, an active stylus includes a transmitter configured to transmit electrical signals to a device through a touch sensor of the device. The active stylus also includes a receiver configured to receive electrical signals from the device through the touch sensor of the device. Furthermore, the active stylus includes a controller configured to determine a strength of an electrical signal received by the receiver from the touch sensor of the device and instruct the transmitter to transmit electrical signals to the device at a voltage based at least on the determined strength of the electrical signal received by the receiver.

Abstract: In one embodiment, an active stylus includes a transmitter configured to transmit electrical signals to a device through a touch sensor of the device. The active stylus also includes a receiver configured to receive electrical signals from the device through the touch sensor of the device. Furthermore, the active stylus includes a controller configured to determine a strength of an electrical signal received by the receiver from the touch sensor of the device and instruct the transmitter to transmit electrical signals to the device at a voltage based at least on the determined strength of the electrical signal received by the receiver.

Abstract: In one embodiment, a method includes receiving at a stylus a receive signal from a device. The stylus includes one or more computer-readable media embodying logic, and the device includes a touch sensor. The receive signal is received at the stylus through the touch sensor of the device and one or more electrodes of the stylus. The method includes filtering the receive signal for processing by the logic and processing, by the logic, the receive signal as filtered.

Abstract: In an embodiment, a system includes a controller coupled to a first set of electrodes. The first set of electrodes are substantially arranged along a first axis. The controller is configured to send a first set of signals through a transmission medium to a first set of electrodes and receive a second set of signals. The impedance of the transmission medium is different than the impedance of the first set of electrodes. The second set of signals include characteristics resulting from effects on the first set of signals from the first set of electrodes and the transmission medium. The controller is configured to change, in response to analyzing the second set of signals, one or more of the following: an impedance of the controller and a voltage associated with the controller.

Abstract: In one embodiment, an apparatus comprises a sense unit and a drive unit. The sense unit is operable to sense a first signal from drive lines of a touch sensor. The touch sensor comprises the drive lines and sense lines arranged relative to the drive lines such that intersections of the drive lines and the sense lines form one or more capacitive nodes. The drive unit is operable to transmit a second signal based on the first signal to the sense lines such that transmission of the second signal changes the perceived capacitance of the one or more capacitive nodes.

Abstract: In one embodiment, a method includes receiving at a stylus a receive signal from a device. The stylus includes one or more computer-readable media embodying logic, and the device includes a touch sensor. The receive signal is received at the stylus through the touch sensor of the device and one or more electrodes of the stylus. The method includes filtering the receive signal for processing by the logic and processing, by the logic, the receive signal as filtered.

Abstract: In one embodiment, at least one resonant circuit in a stylus receives a first signal from a touch sensor of a device. The first signal is received at the resonant circuit by capacitive coupling between the resonant circuit and a conductive element of the device's touch sensor. A second signal based on the first signal and at least one of the at least one resonant circuit is then transmitted from the stylus to the device by capacitive coupling between the stylus and the touch sensor of the device.

Abstract: In an embodiment, a system includes a controller coupled to a first set of electrodes. The first set of electrodes are substantially arranged along a first axis. The controller is configured to send a first set of signals through a transmission medium to a first set of electrodes and receive a second set of signals. The impedance of the transmission medium is different than the impedance of the first set of electrodes. The second set of signals include characteristics resulting from effects on the first set of signals from the first set of electrodes and the transmission medium. The controller is configured to change, in response to analyzing the second set of signals, one or more of the following: an impedance of the controller and a voltage associated with the controller.

Abstract: In one embodiment, at least one resonant circuit in a stylus receives a first signal from a touch sensor of a device. The first signal is received at the resonant circuit by capacitive coupling between the resonant circuit and a conductive element of the device's touch sensor. A second signal based on the first signal and at least one of the at least one resonant circuit is then transmitted from the stylus to the device by capacitive coupling between the stylus and the touch sensor of the device.

Abstract: In one embodiment, an apparatus comprises a sense unit and a drive unit. The sense unit is operable to sense a first signal from drive lines of a touch sensor. The touch sensor comprises the drive lines and sense lines arranged relative to the drive lines such that intersections of the drive lines and the sense lines form one or more capacitive nodes. The drive unit is operable to transmit a second signal based on the first signal to the sense lines such that transmission of the second signal changes the perceived capacitance of the one or more capacitive nodes.