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8-6
136 – 174 MHz VHF Theory of Operation:
Keypad
8.5
Keypad
Left, Right and P1 to P3 keys are directly connected to microprocessor via 22 pin connector. When
any of these keys is pressed, the voltage goes "low" and microprocessor detects it.
For full keypad models, the number keys are in matrix type which consisted of 3 rows and 4 columns.
When any of these keys is pressed, the voltage goes "low" and microprocessor interprets the voltage
for each key press.
Figure 8-4. Keypad Block Diagram
KEY
P
AD
L
e
f
t
N
UMB
ER
S
R
ig
h
t
P1 P2 P
3
K
ey
K
ey
ro
w
K
ey
co
lu
mn
22pin
connector
K
eypa
d
boar
d
22pin
connector
Main
boar
d
MCP
d
etect
Summary of Contents for P100 Series
Page 1: ...P100 Series Portable Radios Detailed Service Manual ...
Page 2: ......
Page 8: ...iv Notes ...
Page 18: ...xiv List of Tables Notes ...
Page 22: ...xviii Summary of Printed Circuit Boards and Bands Available Notes ...
Page 30: ...Notes 2 4 Test Equipment Service Aids and Service Tools Service Aids ...
Page 54: ...7 4 UHF2 Schematic Diagrams Overlays and Parts Lists Speaker and Microphone Schematic Notes ...
Page 128: ...7 78 Circuit Board Schematic Diagram and Parts List UHF2 435 480 MHz Notes ...
Page 150: ...7 100 Circuit Board Schematic Diagram and Parts List UHF2 MDC QCII R TTE 435 470 MHz Notes ...
Page 166: ...10 4 VHF Schematic Diagrams Overlays and Parts Lists Speaker and Microphone Schematic Notes ...
Page 192: ...10 26 Circuit Board Schematic Diagram and Parts List VHF 136 174 MHz Notes ...
Page 218: ...10 52 Circuit Board Schematic Diagram and Parts List VHF 136 174 MHz Notes ...
Page 242: ...10 76 Circuit Board Schematic Diagram and Parts List VHF MDC QCII R TTE 136 174 MHz Notes ...
Page 258: ...13 4 UHF1 Schematic Diagrams Overlays and Parts Lists Speaker and Microphone Schematic Notes ...
Page 328: ...13 74 Circuit Board Schematic Diagram and Parts List UHF1 MDC QCII R TTE 403 447 MHz Notes ...
Page 332: ...A 4 Warranty Service Support and Replacement Parts Further Assistance From Motorola Notes ...
Page 335: ......