platypush.plugins.lcd.i2c

class platypush.plugins.lcd.i2c.LcdI2cPlugin(i2c_expander: str, address: int, expander_params: Optional[dict] = None, port: int = 1, cols: int = 16, rows: int = 2, backlight_enabled: bool = True, dotsize: int = 8, charmap: str = 'A02', auto_linebreaks: bool = True, **kwargs)[source]

Plugin to write to an LCD display connected via I2C. Adafruit I2C/SPI LCD Backback is supported.

Warning: You might need a level shifter (that supports i2c) between the SCL/SDA connections on the MCP chip / backpack and the Raspberry Pi. Or you might damage the Pi and possibly any other 3.3V i2c devices connected on the i2c bus. Or cause reliability issues. The SCL/SDA are rated 0.7*VDD on the MCP23008, so it needs 3.5V on the SCL/SDA when 5V is applied to drive the LCD. The MCP23008 and MCP23017 needs to be connected exactly the same way as the backpack. For complete schematics see the adafruit page at: https://learn.adafruit.com/i2c-spi-lcd-backpack/ 4-bit operation. I2C only supported.

Pin mapping:

7  | 6  | 5  | 4  | 3  | 2 | 1  | 0
BL | D7 | D6 | D5 | D4 | E | RS | -

Requires:

  • RPLCD (pip install RPLCD)

  • RPi.GPIO (pip install RPi.GPIO)

__init__(i2c_expander: str, address: int, expander_params: Optional[dict] = None, port: int = 1, cols: int = 16, rows: int = 2, backlight_enabled: bool = True, dotsize: int = 8, charmap: str = 'A02', auto_linebreaks: bool = True, **kwargs)[source]
Parameters
  • i2c_expander – Set your I²C chip type. Supported: “PCF8574”, “MCP23008”, “MCP23017”.

  • address – The I2C address of your LCD.

  • expander_params – Parameters for expanders, in a dictionary. Only needed for MCP23017 gpio_bank - This must be either A or B. If you have a HAT, A is usually marked 1 and B is 2. Example: expander_params={'gpio_bank': 'A'}

  • port – The I2C port number. Default: 1.

  • cols – Number of columns per row (usually 16 or 20). Default: 16.

  • rows – Number of display rows (usually 1, 2 or 4). Default: 2.

  • backlight_enabled – Whether the backlight is enabled initially. Default: True. Has no effect if pin_backlight is None

  • dotsize – Some 1 line displays allow a font height of 10px. Allowed: 8 or 10. Default: 8.

  • charmap – The character map used. Depends on your LCD. This must be either A00 or A02 or ST0B. Default: A02.

  • auto_linebreaks – Whether or not to automatically insert line breaks. Default: True.