Compass Mirror Description and Operation

Description

The compass function is integrated into the electrochromic inside rear view mirror. The mirror assembly must display the compass direction. The compass mirror then transmits sensor information to determine the static field strength and rotating field information in order to determine the exact compass direction. Specification

Item	Standard Value
Rated Voltage	12 V DC
Operating Voltage Range	DC 9 ~ 16 V
Operating Temperature Range	-30 ~ +65 °C
Direction Display	8
Hold Time	2 sec.

Switching point accuracy: The compass module must compensate for vehicle magnetic fields while variable Earth magnetic fields determine the direction. [Switching Points]

Switch Point	Heading ± 10°
N - NE	22,5
NE - E	67,5
E - SE	112,5
SE - S	157,5
S - SW	202,5
SW - W	247,5
W - NW	292,5
NW - N	337,5

Each switching point must have hysteresis. The switching points between the 8 compass directions are ± 10°.

Compass display interval: The compass display must update every two seconds.

Function

The compass can be turned on and off, and it memorizes the last state when the ignition is turned on. To turn the display function ON or OFF:

1. 1
   Press and release the function control button (A) to turn off the display function.
2. 2
   Press and release the function control button (A) again to turn the display back on. Additional settings can be made by pressing and holding the function control button (A) in sequence, as described in detail below.

   

   There is a difference between magnetic north and true north. The compass in the mirror can compensate for this difference when it knows the magnetic zone in which it operates. This is set either by the dealer or by the user.