Contrast Adjustment - Z-World Fox LP3500 User Manual

C.2 Contrast Adjustment
Depending on when you acquired your LCD/keypad module, you will be able to set the
contrast on the LCD display by adjusting the potentiometer at R2 or by setting the voltage
for 2.8 V by setting the jumper across pins 1–2 on header J5 as shown in Figure C-3. Only
one of these two options is available on a given LCD/keypad module
Contrast
Adjustment
J5
3
4
Figure C-3. LCD/Keypad Module Contrast Adjustment
NOTE: Older LCD/keypad modules that do not have a header at J5 or a contrast adjust-
ment potentiometer at R2 are limited to operate only at 5 V, and will not work with the
LP3500. The older LCD/keypad modules are no longer being sold.
User's Manual
Description
Header
2.8 V
J5
3.3 V
5 V
R2
U3
LCD1
Q1
J5
R25
1
R8
R26
2
R11
R13
J5
3
1
Q4
Q6
4 2
OTHER LP3500
3.3 V
2.8 V
n.c. = 5 V
KP1
RN1
C17
Pins
Connected
1–2
3–4
n.c.
D2 C1
D1 JP1
C4
R3
C6
U1
U2
C9 C7
R4
R5
C11
U4
J1
R10 R9 R12
R14
R15
Q2 Q5
Q7
Q8
U5
U6
J2
U7 C14
DISPLAY
J4
Factory
Default
×
CR1
C13
C12
BOARD
87