Ui Board - Nokia NPL-4 Series Manual

Nokia Customer Care

UI Board

NPL-4/5 consists of separate UI board, type designate wk4, which includes contacts for
the keypad domes, Functional cover interface pads, Thermoter thermistor and LED's for
keypad lighting. UI board is connected to main PWB through 20 pole board-to-board
connector with springs.
5x5-matrix keyboard is used in NPL-4/5. Key pressing is detected by scanning procedure.
Keypad signals are connected UPP keyboard interface.
UPP
EMIF10 ASIP
EMC filter
ROW 0
ROW 1
ROW 2
ROW 3
ROW 4
COL 0
COL 1
COL 2
COL 3
COL 4
When no key is pressed, row inputs are high due to UPP internal pull-up resistors. The
columns are written zero. When key is pressed one row is pulled down and an interrupt is
generated to MCU. After receiving interrupt, MCU starts scanning procedure. All columns
Copyright © 2005 Nokia Corporation. All rights reserved.
Issue 2 05/05
Figure 26: Display Block
Figure 27: UI Board
vol
left end
send
up
vol
s do
up
dow
left wn
n
1 4 7
se
2 5 8
lect
PTT 3 6 9
System Module and User Interface
right
s
right
UEMEk
*
0
#
PWRONX
NPL-4/5/
Power
Switch
EMC
filter
Page 67