Introduction

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This library is compatible with standard Character LCDs such as:

• Adafruit Standard LCD 16x2 <https://www.adafruit.com/product/181>_
• Adafruit RGB backlight negative LCD 16x2 <https://www.adafruit.com/product/399>_
• Adafruit RGB backlight negative LCD 20x4 <https://www.adafruit.com/product/498>_

Installing from PyPI

On supported GNU/Linux systems like the Raspberry Pi, you can install the driver locally from PyPI <https://pypi.org/project/adafruit-circuitpython-charlcd/>_. To install for current user:

.. code-block:: shell

pip3 install adafruit-circuitpython-charlcd

To install system-wide (this may be required in some cases):

.. code-block:: shell

sudo pip3 install adafruit-circuitpython-charlcd

To install in a virtual environment in your current project:

.. code-block:: shell

mkdir project-name && cd project-name
python3 -m venv .venv
source .venv/bin/activate
pip3 install adafruit-circuitpython-charlcd

Dependencies

This driver depends on:

• Adafruit CircuitPython <https://github.com/adafruit/circuitpython>_
• Adafruit CircuitPython BusDevice <https://github.com/adafruit/Adafruit_CircuitPython_BusDevice>_
• Adafruit CircuitPython MCP230xx <https://github.com/adafruit/Adafruit_CircuitPython_MCP230xx>_
• Adafruit CircuitPython 74HC595 <https://github.com/adafruit/Adafruit_CircuitPython_74HC595>_

I2C & SPI displays also depend on:

• Bus Device <https://github.com/adafruit/Adafruit_CircuitPython_BusDevice>_

Please ensure all dependencies are available on the CircuitPython filesystem. This is easily achieved by downloading the Adafruit library and driver bundle <https://github.com/adafruit/Adafruit_CircuitPython_Bundle>_.

Usage Example

The Character_LCD class interfaces a predefined Character LCD display with CircuitPython.

.. code-block:: python

import board
import digitalio
import adafruit_character_lcd.character_lcd as character_lcd

You must define the data pins (RS, EN, D4, D5, D6, D7) in your code before using the Character_LCD class. If you want to have on/off backlight functionality, you can also define your backlight as lcd_backlight. Otherwise, the backlight will always remain on. The following is an example setup.

.. code-block:: python

lcd_rs = digitalio.DigitalInOut(board.D7)
lcd_en = digitalio.DigitalInOut(board.D8)
lcd_d7 = digitalio.DigitalInOut(board.D12)
lcd_d6 = digitalio.DigitalInOut(board.D11)
lcd_d5 = digitalio.DigitalInOut(board.D10)
lcd_d4 = digitalio.DigitalInOut(board.D9)
lcd_backlight = digitalio.DigitalInOut(board.D13)

You must also define the size of the CharLCD by specifying its lcd_columns and lcd_rows:

.. code-block:: python

lcd_columns = 16
lcd_rows = 2

After you have set up your LCD, we can make the device by calling it

.. code-block:: python

lcd = character_lcd.Character_LCD_Mono(lcd_rs, lcd_en, lcd_d4, lcd_d5, lcd_d6, lcd_d7, lcd_columns, lcd_rows, lcd_backlight)

To verify that your pins are correct, print a hello message to the CharLCD:

.. code-block:: python

lcd.message = "Hello\nCircuitPython"

Custom character example with create_char() is provided within /examples/

Documentation

API documentation for this library can be found on Read the Docs <https://docs.circuitpython.org/projects/charlcd/en/latest/>_.

For information on building library documentation, please check out this guide <https://learn.adafruit.com/creating-and-sharing-a-circuitpython-library/sharing-our-docs-on-readthedocs#sphinx-5-1>_.

Contributing

Contributions are welcome! Please read our Code of Conduct <https://github.com/adafruit/Adafruit_CircuitPython_CharLCD/blob/main/CODE_OF_CONDUCT.md>_ before contributing to help this project stay welcoming.