LCD

Kaluma library for liquid crystal display (HD44780 driver)

Wiring

Here is a wiring example for LCD (4-bits mode).

Raspberry Pi Pico	LCD	Potentiometer
VBUS	VDD, LED+	+
GND	VSS(GND), LED-, RW	-
GP3	RS
GP5	E
GP6	D4
GP7	D5
GP8	D6
GP9	D7
	V0	OUT (middle)

You may need to adjust the potentiometer to find proper brightness of the display.

Install

npm install https://github.com/niklauslee/lcd

Usage

Here is an example code.

const rs = 3;
const en = 5;
const dp = [6, 7, 8, 9];
const {LCD} = require('lcd');
const lcd = new LCD(rs, en, dp);
lcd.begin();
lcd.print('Hello, world!');

API

Class: LCD

new LCD(rs, en, data)

• rs <number> The pin number for RS (register selection).
• en <number> The pin number for E (enable).
• data <number[]> An array for data pins. Currently only 4-pins mode is supported.

lcd.begin([cols[, rows[, charsz]]])

• cols <number> The number of columns. Default: 16.
• rows <number> The number of rows. Default: 2.
• charsz <number> Indicates the size of character. 0 for 5x8 and 1 for 5x10. Default: 0.

Initialize the display.

lcd.clear()

Clear the display and set cursor position to home (left-top).

lcd.home()

Set cursor position to home (left-top).

lcd.setCursor(col, row);

• col <number>
• row <number>

Move the cursor to the position at (col, row).

lcd.write(value)

• value <number> A character code to write.

Write a character at the cursor position.

lcd.print(str)

• str <string>

Print a string at the cursor position.

lcd.on()

Turn on the display.

lcd.off()

Turn off the display.

lcd.cursor([onoff])

• onoff <boolean> Default: true.

Show the cursor or hide.

lcd.blink([onoff])

• onoff <boolean> Default: true.

Blink the cursor or not.

lcd.scrollLeft()

Scroll the display left.

lcd.scrollRight()

Scroll the display right.

lcd.ltr()

Text flows left to right.

lcd.rtl()

Text flows right to left.

lcd.justifyRight()

Justify text to right from the cursor

lcd.justifyLeft()

Justify text to left from the cursor

lcd.createChar(index, bitmap)

• index <number> Index of the bank where the char to be stored. We have only 8 banks (0~7).
• bitmap <number[]> Bitmap data of the custom character.

Create a custom character.

var smiley = [
  0b00000,
  0b00000,
  0b01010,
  0b00000,
  0b00000,
  0b10001,
  0b01110,
  0b00000
];
lcd.createChar(0, smiley); // store at 0 bank.
lcd.write(0); // write the custom char at 0 bank.