3. TECHNICAL BRIEF
- 41 -
3.8 Keypad Switches and Scanning
The key switches are metal domes, which make contact between two concentric pads on the keypad
layer of the PCB when pressed. There are 27 switches (Normal Key 24EA, Torch side key, Volume up
down side key), connected in a matrix of 5 rows by 5 columns and additional GPIO 35 for
KEY_ROW5, as shown in Figure 3-24, except for the power switch (KB1), which is connected
independently. Functions, the row and column lines of the keypad are connected to ports of AD6527.
The columns are outputs, while the rows are inputs and have pull-up resistors built in.
When a key is pressed, the corresponding row and column are connected together, causing the row
input to go low and generate an interrupt. The columns/rows are then scanned by AD6527 to identify
the pressed key.
RIGHT
6
UP
VOL_DOWN
8
SEND
DOWN
4
0
SEL
FAV
VOL_UP
*
END
#
1
CONF
CLR
7
3
TORCH
2
9
T
LEFT
MENU
5
SW324
SW326
SW310
SW317
SW319
R373
680
SW321
SW320
SW302
SW303
SW309
SW313
SW327
100
R302
R379
680
R304
100
R300
680
SW301
SW300
SW304
VA302
AVL14K02200
SW305
R378
AVL14K02200
VA307
SW314
680
680
R382
R381
680
680
R380
VBAT
680
R386
100
R305
SW325
AVL14K02200
VA300
SW323
SW306
VA304
AVL14K02200
SW307
VA308
AVL14K02200
SW312
SW328
SW315
R372
10K
SW322
SW318
AVL14K02200
VA301
VA303
AVL14K02200
SW311
R301
100
R383
680
680
R377
R376
680
680
R375
SW308
100
R303
SW316
KEY_ROW2
KEY_ROW5
KEY_COL1
KEY_COL0
KEY_COL4
KEY_ROW1
KEY_COL3
KEY_ROW3
KEY_ROW4
KEY_COL2
KEY_ROW0
POWERKEY
Figure 3-27. Keypad Switches and Scanning
Содержание C2100
Страница 1: ...Service Manual Model C2100 Service Manual C2100 P N MMBD0048201 Date April 2005 Issue 1 0 ...
Страница 54: ...4 TROUBLE SHOOTING 55 4 2 TX Trouble SW500 U503 X500 FL500 U501 U505 5 4 1 3 2 Test Points Figure 4 7 ...
Страница 70: ...4 TROUBLE SHOOTING 71 4 7 MIC Trouble Soldering Check U203 C225 C224 C230 Test Points Figure 4 18 ...
Страница 76: ...4 TROUBLE SHOOTING 77 4 10 KEY backlight Trouble Test Points Figure 4 21 ...
Страница 104: ... 105 8 PCB LAYOUT ...
Страница 105: ... 106 8 PCB LAYOUT ...
Страница 113: ...10 STAND ALONE TEST 114 Figure 10 2 HW test setting Figure 10 3 Ramping profile ...
Страница 117: ...Note 118 ...
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