Abstract: Systems and methods for representing and displaying graphical images that tend to minimize the storage and processing requirements for representing such images on devices with limited storage capacity and processing power are provided. Graphical images may be represented and displayed using the follow techniques: the use of vector shapes and bitmap brushes, primitive shape descriptions, hierarchical structures, shape property storage, and small or variable number representation. These techniques may be used independently or in combination in various embodiments, and may lead to small file sizes, fast view rendering, graphical capabilities similar to raster formats, zoom capabilities similar to vector formats, and attribute storage capabilities.

Abstract: Methods and systems for reducing power consumption in data communications is presented. Portable devices that interface with peripheral devices reduce power consumption by minimizing the time that a communications port is open. Rather than keeping the communications port open for the duration of a program, the communications port is opened at calculated times to allow bursts of data to pass through and closed in response to certain events. This invention also works with normal power cycling methods of portable devices and peripheral devices to produce even further power savings.

Abstract: Methods for automatically detecting GPS hardware are provided. The methods attempt to determine the protocol of a GPS receiver by adjusting variables related to the protocol of the GPS receiver. The variables may include baud rate, protocol, or any other desired variable. Following determination of the proper configuration settings, the methods determine the communications port to configure with the appropriate settings.

Abstract: A circuit for controlling a current in a load, the circuit includes: structure for connecting the circuit to a source of power, the power source connecting structure including a power switch having off and on operating modes; structure for connecting the circuit to a supply of a pulse width modulated (PWM) control signal, the PWM supply connecting structure including an AND gate having first and second input structure and an output structure, one of the first and second input structures connected for receiving the PWM control signal, and the AND gate output structure connected to the power switch for operating the switch; structure for monitoring the current in the load, the monitoring structure including a differential amplifier, the differential amplifier having an instantaneous output voltage signal proportional to the load current when the power switch is in the on operating mode, structure for comparing a value derived from the instantaneous signal to a high reference voltage signal and a low reference v

Abstract: An integrated circuit driver for a brushless motor having an encoder which includes a plurality of Hall-effect sensors operative for providing commutation information to a motor controller includes a commutation decoding section for decoding the commutation information from the Hall-effect sensors and an analog current limiter. The current limiter includes a circuit for dynamically switching the current limit values for current in the motor between a high current limit value and a low current limit value based on the average or RMS value of the motor winding current. The current limit values must be provided externally. A Hall-effect sensor quadrature encoder is provided on the integrated circuit and a selection switch allows for the selection of a quadrature output from an external optical encoder or the internal Hall-effect sensor encoder.