Contrast Adjustments For All Boards - Rabbit RabbitCore RCM3100 User Manual

Distributor of Digi International: Excellent Integrated System Limited
Datasheet of 101-0533 - KIT DEV RABBIT3000/RCM3100
Contact us: sales@integrated-circuit.com Website: www.integrated-circuit.com
C.2 Contrast Adjustments for All Boards
Starting in 2005, LCD/keypad modules were factory-configured to optimize their contrast
based on the voltage of the system they would be used in. Be sure to select a KDU5V
LCD/keypad module for use with the RCM3000/3100/3200 Prototyping Board — these
modules operate at 5 V. You may adjust the contrast using the potentiometer at R2 as
shown in Figure C-3. LCD/keypad modules configured for 3.3 V should not be used with
the 5 V RCM3000/3100/3200 Prototyping Board because the higher voltage will reduce
the backlight service life dramatically.
Header
Contrast
Adjustment
J5
3
4
Figure C-3. LCD/Keypad Module Voltage Settings
You can set the contrast on the LCD display of pre-2005 LCD/keypad modules by adjust-
ing the potentiometer at R2 or by setting the voltage for 5 V by removing the jumper across
pins 1–2 on header J5 as shown in Figure C-3. Only one of these two options is available
on these LCD/keypad modules.
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 work with the
Prototyping Board. The older LCD/keypad modules are no longer being sold.
User's Manual
Description
2.8 V
J5 3.3 V
5 V
R2 D2 C1
C9
C7
U3
LCD1
U4
Q1
J5
R25
1
R8
R26
2
R11 R13 R14
J5
3 1
Q4 Q6 Q7
4 2
OTHER LP3500
U6
3.3 V
2.8 V
n.c. = 5 V
U7 C14
KP1
RN1
C17
J4
Pins
Factory
Connected
Default
×
1–2
3–4
n.c.
D1 JP1
C4
R3
C6
U2 U1
R4
R5
CR1
C11
C13
C12
J1
R10 R9 R12
R15
Q2 Q5
Q8
U5
J2
DISPLAY
BOARD
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