Method for adjusting displayed navigation direction using sensors and navigation device using the same

1. A method for adjusting displayed map using sensors, applied in a navigation device, comprising the steps of:

calculating a GPS-based rotating angle of the navigation device based on location information detected by a GPS module of the navigation device when a coordinate error value of the navigation device is less than a predetermined value;

using a sensor of the navigation device to detect a sensor-based rotating angle of the navigation device when the coordinate error value of the navigation device is greater than the predetermined value;

rotating a map on a screen of the navigation device according to one of the GPS-based rotating angle and the sensor-based rotating angle depending on the coordinate error value.

2. The method as claimed in claim 1 , wherein the rotating the map further comprising:

setting a map angle of the map as one of the GPS-based rotating angle and the sensor-based rotating angle; and

rotating the map by the map angle.

3. The method as claimed in claim 1 , wherein rotating a map further comprising: comprises:

defining the sensor-based rotating angle of the sensor, and a current angle of the navigation device;

subtracting the sensor-based rotating angle of the sensor from the GPS-based rotating angle of the navigation device to obtain an angle variation value;

setting a map angle as the current angle plus the angle variation value; and

rotating the map by the map angle.

4. The method as claimed in claim 1 , wherein the sensor is a G/M sensor or a gyroscope.

5. A navigation device, comprising:

a screen for displaying a map;

a GPS module for calculating a GPS-based rotating angle of the navigation device based on a location information detected by the GPS module of the navigation device when a coordinate error value of the navigation device is less than a predetermined value;

a sensor for detecting a sensor-based rotating angle of the navigation device when the coordinate error value of the navigation device is greater than a predetermined value; and

a microprocessor for rotating a map according to one of the GPS-based rotating angle and the sensor-based rotating angle depending on the coordinate error value.

6. The navigation device as claimed in claim 5 , wherein the microprocessor further sets a map angle of the map as one of the GPS-based rotating angle and the sensor-based rotating angle; and rotates the map by the map angle.

7. The navigation device as claimed in claim 5 , wherein the microprocessor further defines the sensor-based rotating angle of the sensor, and a current angle of the navigation device; subtracts the sensor-based rotating angle of the sensor from the GPS-based rotating angle of the navigation device to obtain a angle variation value; sets a map angle as the current angle plus the angle variation value; and rotates the map by the map angle.

8. The navigation device as claimed in claim 5 , wherein the sensor is a G/M sensor or a gyroscope.