11-6
403 – 447 MHz UHF1 Theory Of Operation:
Keypad
11.5 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 11-4. 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
Содержание CP Series
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Страница 127: ...Circuit Board Schematic Diagram and Parts List UHF1 403 447 MHz 13 2 Figure 13 4 VCO and PLL Schematic Diagram ...
Страница 128: ...13 3 Circuit Board Schematic Diagram and Parts List UHF1 403 447 MHz Figure 13 5 Transmitter Schematic Diagram ...
Страница 131: ...Circuit Board Schematic Diagram and Parts List UHF1 403 447 MHz 13 6 Figure 13 8 Switches and Battery Schematic Diagram ...
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