i2c-lcd

Kaluma library for liquid crystal display with PCF8574 I2C port expander (LCM1602 module)

Prerequisite

Get Kaluma

Install

npm install https://github.com/slashinfty/i2c-lcd

Usage

Assuming the following wiring (and powered by USB):

Pico	LCM1602
VBUS	VCC
GND	GND
GP2	SDA
GP3	SCL

const { LCD } = require('lcd');
const lcd = new LCD();
lcd.begin();

Examples

Coming soon.

API - Class: LCD

Constructor

• new LCD(busNumber, address, cols, rows)

Name	Default	Description
busNumber	1	bus number of the i2c device
address	0x27	address of the i2c device
cols	16	character width of the display
rows	2	number of lines in the display

Properties (read-only)

• busNumber
  • the bus number declared when instantiating the LCD object
• address
  • the i2c address declared when instantiating the LCD object
• cols
  • the number of characters width declared when instantiating the LCD object
• rows
  • the number of lines declared when instantiating the LCD object
• began
  • true if the LCD has been initialized, false if not

Instance Methods

• begin()
  • initializes the interface to the LCD screen
  • must be called before any command
• clear()
  • clears the LCD screen and positions the cursor in the upper-left corner
• home()
  • positions the cursor in the upper-left of the LCD
• setCursor(col, row)
  • positions the LCD cursor to the specified location
• print(str)
  • prints text to the LCD at the cursor location
• printLine(line, str)
  • prints text to the LCD on the specified line
• cursor()
  • displays the LCD cursor (underscore line)
• noCursor()
  • hides the LCD cursor
• blink()
  • displays the blinking LCD cursor (white block)
• noBlink()
  • turns off the blinking LCD cursor
• display()
  • turns on the LCD display
• noDisplay()
  • turns off the LCD display
• scrollDisplayLeft()
  • scrolls the contents of the display (text and cursor) one space to the left
• scrollDisplayRight()
  • scrolls the contents of the display (text and cursor) one space to the right
• leftToRight()
  • sets the direction for text written to the LCD to left-to-right (default)
• rightToLeft()
  • sets the direction for text written to the LCD to right-to-left
• createChar(id, data)
  • creates a custom character (glyph) for use on the LCD
  • up to eight characters of 5x8 pixels are supported (id 0 to 7)
  • the appearance of each custom character is specified by an array of eight bytes, one for each row
  • the five least significant bits of each byte determine the pixels in that row
  • to display a custom character on the screen, use print(LCD.getChar(id))
  • for more information on creating characters, check out this tool

Static Methods

• getChar(id)
  • gets the custom character stored at the specified id

Inspiration

• raspberrypi-liquid-crystal (npm package)
• lcd (Kaluha library)