Serial Input
The Liquid Crystal Library allows you to control LCD displays that are compatible with the Hitachi HD44780 driver. There are many of them out there, and you can usually tell them by the 16-pin interface.
This example sketch accepts serial input from a host computer and displays it on the LCD. To use it, upload the sketch, then open the Serial Monitor and type some characters and click Send. The text will appear on your LCD.
Hardware Required
- Arduino or Genuino Board
- LCD Screen (compatible with Hitachi HD44780 driver)
- pin headers to solder to the LCD display pins
- 10k ohm potentiometer
- 220 ohm resistor
- hook-up wires
- breadboard
Software
- A computer running the Arduino Software (IDE)
Circuit
Before wiring the LCD screen to your Arduino or Genuino board we suggest to solder a pin header strip to the 14 (or 16) pin count connector of the LCD screen, as you can see in the image above.
To wire your LCD screen to your board, connect the following pins:
- LCD RS pin to digital pin 12
- LCD Enable pin to digital pin 11
- LCD D4 pin to digital pin 5
- LCD D5 pin to digital pin 4
- LCD D6 pin to digital pin 3
- LCD D7 pin to digital pin 2
Additionally, wire a 10k pot to +5V and GND, with it's wiper (output) to LCD screens VO pin (pin3). A 220 ohm resistor is used to power the backlight of the display, usually on pin 15 and 16 of the LCD connector
click the images to enlarge
image developed using Fritzing. For more circuit examples, see the Fritzing project page
Schematic
click the images to enlarge
image developed using Fritzing. For more circuit examples, see the Fritzing project page
Code
You need to connect the board to your computer and use the Arduino Software (IDE) serial monitor to communicate with it.
/*
LiquidCrystal Library - Serial Input
Demonstrates the use a 16x2 LCD display. The LiquidCrystal
library works with all LCD displays that are compatible with the
Hitachi HD44780 driver. There are many of them out there, and you
can usually tell them by the 16-pin interface.
This sketch displays text sent over the serial port
(e.g. from the Serial Monitor) on an attached LCD.
The circuit:
* LCD RS pin to digital pin 12
* LCD Enable pin to digital pin 11
* LCD D4 pin to digital pin 5
* LCD D5 pin to digital pin 4
* LCD D6 pin to digital pin 3
* LCD D7 pin to digital pin 2
* LCD R/W pin to ground
* 10K resistor:
* ends to +5V and ground
* wiper to LCD VO pin (pin 3)
Library originally added 18 Apr 2008
by David A. Mellis
library modified 5 Jul 2009
by Limor Fried (http://www.ladyada.net)
example added 9 Jul 2009
by Tom Igoe
modified 22 Nov 2010
by Tom Igoe
modified 7 Nov 2016
by Arturo Guadalupi
This example code is in the public domain.
http://www.arduino.cc/en/Tutorial/LiquidCrystalSerialDisplay
*/
// include the library code:
#include <LiquidCrystal.h>
// initialize the library by associating any needed LCD interface pin
// with the arduino pin number it is connected to
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
void setup() {
// set up the LCD's number of columns and rows:
lcd.begin(16, 2);
// initialize the serial communications:
Serial.begin(9600);
}
void loop() {
// when characters arrive over the serial port...
if (Serial.available()) {
// wait a bit for the entire message to arrive
delay(100);
// clear the screen
lcd.clear();
// read all the available characters
while (Serial.available() > 0) {
// display each character to the LCD
lcd.write(Serial.read());
}
}
}
See Also
- Hello World! – How to wire an LCD display and bring it to life.
- Blink - Control of the block-style cursor.
- Cursor - Control of the underscore-style cursor.
- Display - Quickly blank the display without losing what's on it.
- TextDirection - Control which way text flows from the cursor.
- Scroll - Scroll text left and right.
- SetCursor - Set the cursor position.
- Autoscroll - Shift text right and left.
Last revision 2015/08/17 by SM