Control character LCDs with your Pi using JavaScript!
This library has only been tested on 16x2 displays, but it should work for others.
The character set of the Hitachi HD44780UA00 (The most used character LCD screen controller) is mostly ascii but with some minor differences.
- If you send it a backslash, ("\\") it will display a yen symbol (¥)
- If you send it a tilde, ("~") it will display a left-arrow (←)
- If you send it a DEL character, ("\x7f") it will display a right-arrow (→)
The characters beyond 0x7f include japanese katakana, some greek letters, and mathematical symbols. Check this out for more info!
const rpio = require("rpio");
const {LCDScreen} = require("rpio-lcd");
// Initialize an LCD screen!
const screen = new LCDScreen({
// pins: [registerSelect, d4, d5, d6, d7]
pins: [11, 13, 15, 16, 18],
// This is optional, you can specify a ShiftRegister from "rpio-shift" here if the above pins are connected to one
dataIO: null,
// This is the enable pin on the LCD
clockPin: 12,
// This is optional, you can specify a ShiftRegister from "rpio-shift" here if the above pin is connected to one
clockIO: null
})
// screen.displayOn(bool)
// If true, the display is shown. You can still write or send commands to the LCD while the screen is hidden
// This is enabled by default
screen.displayOn(true);
// screen.cursorBlink(bool)
// If true, the cursor will blink
// This is enabled by default
screen.cursorBlink(true);
// screen.cursorUnderscore(bool)
// If true, an underscore will be shown at the cursor position
// This is disabled by default
screen.cursorUnderscore(false);
// screen.clear()
// Clears the screen and returns the cursor to the home position
screen.clear();
// screen.cursorLeft()
// Moves the cursor one space to the left
screen.cursorLeft();
// screen.cursorLeft()
// Moves the cursor one space to the right
screen.cursorRight();
// screen.cursorHome()
// Moves the cursor to the beginning of the first line
screen.cursorHome();
// screen.cursorSecondLine()
// Moves the cursor to the beginning of the second line
screen.cursorSecondLine();
// screen.textLeft()
// Moves the text on screen to the left
screen.textLeft();
// screen.textRight()
// Moves the text on screen to the right
screen.textRight();
// screen.writeMode(goRight, moveScreen)
// If goRight is true, the cursor will move right when text is written, else, it'll go left.
// if moveScreen is true, the text will be moved opposite to the cursor position when text is written. useful for scrolling text
screen.writeMode(true, false);
// screen.setCustomChar(code, bufferOrArray)
// Allows you to specify a custom character. This is stored in the LCD's RAM so it will be lost when the LCD is powered off.
// You can store 8 custom characters with codes 0 to 7.
// For example, to display the following image:
/*
░███░
█░░░█
█░░░█
░███░
█░█░░
░██░█
░░██░
░░█░░
*/
// It is encoded as so, where 1 is a filled pixel and 0 is an unfilled one
screen.setCustomChar(0, [
0b01110,
0b10001,
0b10001,
0b01110,
0b10100,
0b01101,
0b00110,
0b00100
]);
// screen.writeText(stringOrBuffer)
// Output some text on the screen
screen.writeText("Hello, world!");
// Output all your custom characters
screen.writeText("\x00\x01\x02\x03\x04\x05\x06\x07")
// Note that \n doesn't work here. Use screen.cursorSecondLine().
// Please see the note at the beginning of the readme regarding the character set.