LCD Shield is a 16x2 LCD (Liquid Crystal Display) compact module, ready to embed to Arduino header.
So, the stackable shield can directly be programmed and used (plug n play)
above Arduino Uno board. The boards compatible with the shield are Arduino/Genuino
Uno, Mega, Leonardo, and Duemilanove. The LCD module (usually using a Hitachi
HD44780) has built in minimum circuit, so you do not need to create your own.
Even, it’s already provided several buttons that can be used as a navigation
menu on the LCD.
LCD Shield Pinout Configuration
Since it was shaped as a shield, then control pins are also specified
by the manufacturer, so we can’t use another pin in Arduino (which are connected
LCD pinouts directly) to control it. Arduino pin that's already been reserved
for control the shield are:
Pin
|
Function
|
8
|
RS
(Register Select)
|
9
|
EN (enable)
|
4
|
Data-4
(D0 in 4-bit mode)
|
5
|
Data-5 (D1 in
4-bit mode)
|
6
|
Data-6
(D2 in 4-bit mode)
|
7
|
Data-7 (D3 in
4-bit mode)
|
Thus we MANDATORY use the pins when initializing LCD in our
Arduino sketch. You may directly control the LCD shield using command ‘digitalWrite’
in question, but for simplicity's sake, I recommend using an existing LiquidCrystal.h
library. You can define this library directly at the top of your sketch because
it's a default/built in Arduino library.
Arduino-LCD Shield Sketch Handler
Here is an example to show 'Hello World' on the LCD shield
using Arduino script.
#include <LiquidCrystal.h>
LiquidCrystal lcd(8, 9, 4, 5, 6, 7);
void setup() {
lcd.begin(16, 2);
lcd.print("Hello World");
}
void loop() {
lcd.setCursor(0, 1);
lcd.print("ArduinoGeek.com");
}
Note that in line [1], we must define ‘LiquidCrystal’ library,so all functions in this library can be used. Next, in line [2]
we need to define the pins used in this LCD shield (see on table above). Next we
need to initialize the LCD shield with lcd.begin (16.2); in block setup (see
row [4]). And to display 'Hello World' text on LCD shield, you can easily do
with function lcd.print (row [5]).
You did it. Easy enough, right? So in essence, working with
LCD shield and a normal LCD (with a minimum circuit created your own) are equal
either of library usage and how to access control pins. The difference is if works
with LCD shield, control pins connection in Arduino pins were already
determined and can’t be changed, whereas if you use a non LCD shield you can
configure it by yourself. So its concerns are dependent on your system design,
if you use LCD shield, everything (dimension, header, pinouts) has been
determined and we have to follow, while using the bare LCD we can be more
flexible (custom) in designing our own system ( PCB size, PCB layout, enclosure
dimension, etc).
In the next tutorial I’ll demonstrated this library usage to
create an RPM meter for motors DC / AC.
A blogger, electro-hobbyst, freelancer n technopreneur. I'm an Indonesian, I did my best to make tutorial without spelling errors, please CMIIW or if something burned your eyes..
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