Nokia 7280 Service Manual

Page of 42
ISSUE 1 11/04
COMPANY CONFIDENTIAL
29
Copyright © 2004 Nokia. All Rights Reserved.
RM-14
7 - System Module
Nokia Customer Care
Whether the rotator movement is CW (down) or CCW (up) can thus be decoded by comparing 
the interrupt pin with the stage of the last interrupt.
■ 
Slide switch 
A switch is needed to detect the position of the slide.
Connection to the engine:
This switch is implemented with a hall IC and a magnet. The hall IC is SH248CSP from Sam-
sung. 
Figure 14: The switch
The signal from the Hall IC is connected to the analog keyboard input (AuxDet) in the UEME, 
as this also is an interrupt input. This allows the phone to wake up, by opening the phone.
Analog keyboard input is used due to interrupt possibilities and because the Hall IC requires a 
minimum supply voltage of 2.7V. 
The Hall solution requires a magnet, which is placed on top of Hall-IC, and is moved away from 
the sensor with the moving mechanics, thus making a change of the magnetic field. The mag-
net has the dimensions 5x3x1 mm and is mounted in the top of the phone in the sliding part.
Connecting 
pin
Connecting 
IC
Function
Open/
Closed
AuxDet
UEME
Output from Hall IC tells if slide is open or 
closed
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