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char-lcd v0.0.4

Character LCD display emulator

# char-lcd


Character LCD display emulator

Emulate Hitachi HD44780 and compatible devices in HTML

HD44780-A00 (Japanese standard font)


HD44780-A02 (European standard font)



npm install char-lcd --save
or bower install char-lcd
or yarn add char-lcd
or clone the whole project from GitHub


Web Component (Polymer)

Plain HTML
<script src="char-lcd.js"></script>
CDN (always the latest version!)
<script src=""></script>
var CharLCD = require('char-lcd');
require(['char-lcd'], function(CharLCD) {
  // ...


<div id=lcd></div>
var lcd = new CharLCD({ at: 'lcd', rows: 2, cols: 16, rom: 'eu' });
// Map UNICODE string to the internal character set:
lcd.text(0, 0, "ЁЛКИ-ПАЛКИ!");



var lcd = new CharLCD(params);
params is an object with the following keys:

  • at: a DOM element in which to place the object, or its id; default: at the bottom of the page;
  • rom: jp (default) for Japanese standard font, or eu for European standard font.
  • rows: - number of rows; default: 2;
  • cols: - number of columns; default: 16;

Unlike the real hardware where only certain combinations of rows/cols exist, there are no restrictions in the simulator;

char(r, c, h)

lcd.char(r, c, h); - set the character at row r, column c to byte h.

text(r, c, s)

lcd.text(r, c, s); - print string s at row r, column c.
This function treats \n as new line and maps UNICODE characters to the internal character set.

font(n, data)

lcd.font(n, data); - define the pixels for the n-th character; data is an array of up to 10 bytes.
In real hardware, only first 8 characters can be changed, but there is no such limitation in the simulator.

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