README.rst

RPLCD

A Python 3/2 Raspberry PI Character LCD library for the Hitachi HD44780 controller. It supports both GPIO (parallel) mode as well as boards with an I2C port expander (e.g. the PCF8574 or the MCP23008).

This library is inspired by Adafruit Industries' CharLCD library as well as by Arduino's LiquidCrystal library.

No external dependencies (except the RPi.GPIO library, which comes preinstalled on Raspbian) are needed to use this library.

If you're trying to get started with RPLCD, you should probably read the docs :)

Setup

You can install RPLCD directly from PyPI using pip:

$ sudo pip install RPLCD

If you want to use I2C, you also need smbus:

$ sudo apt install python-smbus

You can also install the library manually without pip. Either just copy the scripts to your working directory and import them, or download the repository and run python setup.py install to install it into your Python package directory.

Features

Implemented

• Simple to use API
• Support for both 4 bit and 8 bit modes
• Support for both parallel (GPIO) and I²C connection
• Support for custom characters
• Support for backlight control circuits
• Built-in support for A00 and A02 character tables
• Python 2/3 compatible
• Caching: Only write characters if they changed
• No external dependencies (except RPi.GPIO, and python-smbus if you need I²C support)

Wishlist

These things may get implemented in the future, depending on my free time and motivation:

• MicroPython port

Supported I²C Port Expanders

• PCF8574 (used by a lot of I²C LCD adapters on Ali Express)
• MCP23008 (used in Adafruit I²C LCD backpack)
• MCP23017

Documentation

• Stable (released on PyPI): http://rplcd.readthedocs.io/en/stable/
• Latest (current master): http://rplcd.readthedocs.io/en/latest/

Testing

Interactive Test Script

To test your LCD, please run the lcdtest.py script with the testsuite target.

Unit Tests

There are also unit tests. First, install dependencies:

pip install -U -r requirements-dev.txt

Then run the tests:

py.test -v

Coding Guidelines

PEP8 via flake8 with max-line-width set to 99 and E126-E128,C901 ignored:

flake8 --max-line-length=99 --ignore=E126,E127,E128,C901 RPLCD/lcd.py

Resources

• TC2004A-01 Data Sheet: http://www.adafruit.com/datasheets/TC2004A-01.pdf
• HD44780U Data Sheet: http://www.adafruit.com/datasheets/HD44780.pdf

License

This code is licensed under the MIT license, see the LICENSE file or tldrlegal for more information.