Abstract: In one embodiment, a stylus includes a controller, a delay line, a coefficient line and a computer-readable non-transitory storage medium. The controller is operable to receive a synchronization signal that is transmitted from a computing device and received by the stylus. The delay line is operable to store a first consecutive edges of the synchronization signal. The coefficient line includes a pre-determined coefficient vector.

Abstract: In one embodiment, a stylus includes a controller, a delay line, a coefficient line and a computer-readable non-transitory storage medium. The controller is operable to receive a synchronization signal that is transmitted from a computing device and received by the stylus. The delay line is operable to store a first consecutive edges of the synchronization signal. The coefficient line includes a pre-determined coefficient vector.

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 includes a receiver for receiving signals wirelessly transmitted by a device. The stylus can alternate, during a first period of time, power supplied to the receiver between a first power for a first duration and a second power for a second duration. The first power is greater than the second power. The stylus can determine how many events exceeding an event criteria occurred the each first duration, and if the events exceed a threshold, the stylus can initiate wakeup components in the stylus for communicating with the device by initiating a provision of third power to those components. The third power is greater than the first power. When the first period of time expires, the stylus can provide low power to the receiver for a second period of time.

Abstract: In certain embodiments, a method includes wirelessly receiving, by an electrode of a stylus, a signal sent from a touch sensor of a computing device. The received signal includes a data bit and is based on a predefined code sequence. The method also includes producing, by the electrode of the stylus, a derivative signal from the received signal, the derivative signal corresponding to a derivative with respect to time of the received signal. The method further includes performing, by the stylus, a cross-correlation of the derivative signal and an expected-signal pattern, the expected-signal pattern based on a derivative with respect to time of the predefined code sequence, where the cross-correlation produces a cross-correlation signal including one or more cross-correlation pulses. The method also includes determining, by the stylus, based on the cross-correlation signal, that the received signal is associated with the predefined code sequence.

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 includes a receiver for receiving signals wirelessly transmitted by a device. The stylus can alternate, during a first period of time, power supplied to the receiver between a first power for a first duration and a second power for a second duration. The first power is greater than the second power. The stylus can determine how many events exceeding an event criteria occurred the each first duration, and if the events exceed a threshold, the stylus can initiate wakeup components in the stylus for communicating with the device by initiating a provision of third power to those components. The third power is greater than the first power. When the first period of time expires, the stylus can provide low power to the receiver for a second period of time.

Abstract: In one embodiment, a method performed by an active stylus includes wirelessly receiving a synchronization signal from a touch controller. The method also includes determining a synchronization parameter of the synchronization signal, the synchronization parameter including an integer part and a fractional part, the integer part representing a positive integer multiple of an active-stylus clock period and the fractional part representing a fractional portion of the active-stylus clock period. The method further includes wirelessly transmitting information for reception by the touch controller, where the information includes a series of data portions, a successive data portion in the series being separated from a preceding data portion by a time interval. The time interval is based at least in part on the active-stylus clock period, the integer part of the synchronization parameter, and an updated fractional error value.

Abstract: In one embodiment, a method performed by an active stylus includes wirelessly receiving a synchronization signal from a touch controller. The method also includes determining a synchronization parameter of the synchronization signal, the synchronization parameter including an integer part and a fractional part, the integer part representing a positive integer multiple of an active-stylus clock period and the fractional part representing a fractional portion of the active-stylus clock period. The method further includes wirelessly transmitting information for reception by the touch controller, where the information includes a series of data portions, a successive data portion in the series being separated from a preceding data portion by a time interval. The time interval is based at least in part on the active-stylus clock period, the integer part of the synchronization parameter, and an updated fractional error value.

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 a synchronization signal from a computing device and determining a first time associated with detection of a first edge of the synchronization signal. The method also includes determining a second time associated with detection of a second edge of the synchronization signal and determining whether the second time occurs within a first predetermined window of time from the first time. The method further includes, if the second time occurs within the first predetermined window of time from the first time, then determining that the synchronization signal is valid.

Abstract: In one embodiment, a stylus includes a controller, a delay line, a coefficient line and a computer-readable non-transitory storage medium. The controller is operable to receive a synchronization signal that is transmitted from a computing device and received by the stylus. The delay line is operable to store a first consecutive edges of the synchronization signal. The coefficient line includes a pre-determined coefficient vector.

Abstract: Operating a battery management and protection system includes generating a set of events each of which has a respective frequency F/n1, F/n2 . . . F/nm, where ni are integers. One or more of the events are provided to one or more modules in the system. The events, which are generated and provided to the modules independently of a central processing unit, trigger performance of respective actions by the modules.

Abstract: In one embodiment, a method includes receiving a synchronization signal from a computing device and determining a first time associated with detection of a first edge of the synchronization signal. The method also includes determining a second time associated with detection of a second edge of the synchronization signal and determining whether the second time occurs within a first predetermined window of time from the first time. The method further includes, if the second time occurs within the first predetermined window of time from the first time, then determining that the synchronization signal is valid.

Abstract: Operating a battery management and protection system includes generating a set of events each of which has a respective frequency F/n1, F/n2 . . . F/nm, where ni are integers. One or more of the events are provided to one or more modules in the system. The events, which are generated and provided to the modules independently of a central processing unit, trigger performance of respective actions by the modules.

Abstract: A battery management and protection system can include various features to improve safety-critical and other functions. Among the features that can be included in some implementations are automatic loading of safety or other parameters during start-up of the system; a centralized timekeeper and an event system that can trigger actions in the system independently of a central processing unit; use of the same modules for both automatically-controlled safety-related measurements and firmware-controlled measurements; enhanced diagnostic features, and a sleepwalking feature that allows certain modules in the system to continue to perform various functions even when the module or the system is in a low-power sleep mode.

Abstract: A battery management and protection system can include various features to improve safety-critical and other functions. Among the features that can be included in some implementations are automatic loading of safety or other parameters during start-up of the system; a centralized timekeeper and an event system that can trigger actions in the system independently of a central processing unit; use of the same modules for both automatically-controlled safety-related measurements and firmware-controlled measurements; enhanced diagnostic features, and a sleepwalking feature that allows certain modules in the system to continue to perform various functions even when the module or the system is in a low-power sleep mode.

Abstract: A modulator can be configured to sense a change in current flow in a circuit and to generate an oversampled, noise-shaped signal. A first decimation filter is coupled to the modulator and is configured to generate instantaneous current data at a first data rate. The instantaneous current data can be input into a multiplier circuit. The output of the multiplier circuit (the instantaneous current data squared) can be input to a second decimation filter. The second decimation filter can be configured to generate a sum of the squared current data at a second data rate. The sum of the squared current data can be used by an application (e.g., battery power management) to compute power measurements or for other purposes.

Abstract: A battery management and protection system can include various features to improve safety-critical and other functions. Among the features that can be included in some implementations are automatic loading of safety or other parameters during start-up of the system; a centralized timekeeper and an event system that can trigger actions in the system independently of a central processing unit; use of the same modules for both automatically-controlled safety-related measurements and firmware-controlled measurements; enhanced diagnostic features, and a sleepwalking feature that allows certain modules in the system to continue to perform various functions even when the module or the system is in a low-power sleep mode.

Abstract: Operating a battery management and protection system includes generating a set of events each of which has a respective frequency F/n1, F/n2 . . . F/nm, where ni are integers. One or more of the events are provided to one or more modules in the system. The events, which are generated and provided to the modules independently of a central processing unit, trigger performance of respective actions by the modules.