norcaluavs/circuitpython_lcd

CircuitPython library for HD77480 LCD character displays with an I2C backpack. Currently PCF8574 is supported.

Introduction

CircuitPython library for HD77480 LCD character displays with an I2C backpack. Currently PCF8574 is supported.

The original code started with the RPLCD library by Danilo Bargen, in https://github.com/dbrgn/RPLCD, but it has been reworked considerably.

On SAMD21 (M0) boards, lcd/lcd.py is too big to use as .py. Use mpy-cross to convert the .py files into .mpy. Also, use the minimal branch, to save space, if you don't need all the features in the main branch.

Usage Example

The LCD supports character LCDs using the HD77480 chip.

The interface to the LCD is separated into an Interface class. Currently there is only one such class: I2CPCF8574Interface.

import board

from lcd.lcd import LCD
from lcd.i2c_pcf8574_interface import I2CPCF8574Interface

from lcd.lcd import CursorMode

# Talk to the LCD at I2C address 0x27.
# The number of rows and columns defaults to 4x20, so those
# arguments could be omitted in this case.
lcd = LCD(I2CPCF8574Interface(board.I2C(), 0x27), num_rows=4, num_cols=20)

lcd.print("abc ")
lcd.print("This is quite long and will wrap onto the next line automatically.")

lcd.clear()

# Start at the second line, fifth column (numbering from zero).
lcd.set_cursor_pos(1, 4)
lcd.print("Here I am")

# Make the cursor visible as a line.
lcd.set_cursor_mode(CursorMode.LINE)