Abstract: Systems, devices and methods are provided for more efficient use of RAM and other resources in connection with a route calculation algorithm which quickly obtains a best or reasonable best path between two locations. The navigational aid device includes forced layer switching capabilities. The navigational aid device includes a processor and a memory adapted to communicate with the processor. The memory has cartographic data including any number of locations and data indicative of thoroughfares of a plurality of types connecting certain ones of the locations. The plurality of thoroughfares are organized in a hierarchy of detail levels. The processor operates on a route calculation algorithm to find a path between any two of the number of locations and the route calculation algorithm dynamically forces switching between different levels in the hierarchy of detail levels based on a set of criteria.

Abstract: A portable, handheld electronic navigation device includes an altimeter and a GPS unit. An internal memory stores cartographic data, for displaying the cartographic data on a display of the navigation device. Accordingly, the device is capable of displaying cartographic data surrounding a location of the unit as determined by GPS and altitude information as determined by the barometric altimeter and GPS. The device provides an enhancement of the calibration and hence the accuracy of barometric altimeter measurements with the aid of derived altitudes from a GPS. The device is able to determine the need for calibration and perform the subsequent computations necessary to facilitate the calibration. Furthermore, the device is able to determine a correction quantity that should be applied to barometric altitude readings, thereby allowing the device to be calibrated while in motion. Both of these features ultimately result in a more accurate determination of altitude.

Abstract: A computer program, method, and device for controlling the brightness of a display (10) by proportionally varying the voltage delivered to each pixel in the display (10) after the back light (12) for the display (10) has been dimmed to its approximate lowest level. The display (10) includes a back light (12); a display module (16) having an array of pixels that may be individually controlled to selectively block or pass light from the back light (12) to create a desired image; a user interface (24) for selectively adjusting brightness of the back light (12) to vary the amount of light passing through the pixels to control the brightness of the image; and a controller (22) for proportionally adjusting the luminosity of the pixels to further control the amount of light passing through the pixels to control the brightness of the image.

Abstract: Systems, devices and methods are provided for an improved navigational route planning device which provides more understandable, accurate and timely route calculation capabilities. The navigational aid device with route calculation capabilities includes a processor connected to a memory. The memory includes cartographic data and a desired destination, the cartographic data including data indicative of thoroughfares of a plurality of types. A display is connected to the processor and is capable of displaying the cartographic data. The device is adapted to calculate a route to navigate to the desired destination. And, the device is adapted to adjust a starting point for the route calculation to an appropriate location such that the device is on the route at a time when the route calculation is completed. The device processes travel along the route, recognizes when the device has deviated from the route, and calculates a new route to navigate to the desired destination.