User`s guide

Liquid Crystal Displays or LCDs are cheap and
popular way of representing information to the
end user of some electronic device. Character
LCDs can be used to represent standard and
custom characters in the predened number of
elds. EasyPIC
v7 provides the connector and the
necessary interface for supporting 2x16 character
LCDs in 4-bit mode. This type of display has two rows
consisted of 16 character elds. Each eld is a 7x5 pixel
matrix. Communication with the display module is done
through CN7 display connector. Board is tted with uniquely
designed plastic display distancer, which allows the LCD module
to perfectly and rmly t into place.
GND and VCC - Display power supply lines
Vo - LCD contrast level from potentiometer P4
RS - Register Select Signal line
E - Display Enable line
R/W - Determines whether display is in Read or Write mode. It’s
always connected to GND, leaving the display in Write mode all
the time.
D0–D3 - Display is supported in 4-bit data mode, so lower half of
the data byte interface is connected to GND.
D4–D7 - Upper half of the data byte
LED+ - Connection with the back-light LED anode
LED- - Connection with the back-light LED cathode
We have allowed LCD back-light to be enabled in two dierent
ways:
1. It can be turned on with full brightness using SW4.6 switch.
2. Brightness level can be determined with PWM signal from the
microcontroller, allowing you to write custom back-light controlling
software. This back-light mode is enabled with SW4.5 switch.
LCD 2x16 characters
Vss
Vdd
Vee
RS
R/W
E
D0
D1
D2
D3
D4
D5
D6
D7
A
K
CN7
LCD SOCKET
VCC-5V
P4
10K
VCC-5V
Q11
BC846
R93
56
R89
4K7
R10
1K
VCC-MCU
Vee
GND
GND
GND
GND
GND
GND
RB3
RB2
RB1
RB0
RB5
RB4
K-LCD
LCD-GLCD BPWM
LCD-GLCD BCK
1 2 3 4 5 6 7 8
O
N
SW4
LCD-GLCD BPWM RC2
VCC-5V
DATA BUS
Figure 11-1: On-board LCD 2x16 display connector
Figure 11-2: 2x16 LCD
connection schematic
Standard and PWM-driven back-light
Connector pinout explained
Make sure to turn o the power supply before placing LCD onto
the board. Otherwise your display can be permanently damaged.
In order to use PWM back-light both SW4.5 and SW4.6 switches must
be enabled at the same time.
IMPORTANT:
IMPORTANT:
page 24
displays