Using mode 12:
When using I2C LCD mode 12 the target I2C device address is setup as
shown below. Each bit of the the variable i2c_lcd_byte is defined to
address the correct LCD display port.
i2c_lcd_e = i2c_lcd_byte.4 ' <<< the default Enable bit mapping for mode 12
i2c_lcd_rw = i2c_lcd_byte.5
i2c_lcd_rs = i2c_lcd_byte.6
i2c_lcd_bl = i2c_lcd_byte.7
i2c_lcd_d4 = i2c_lcd_byte.0
i2c_lcd_d5 = i2c_lcd_byte.1
i2c_lcd_d6 = i2c_lcd_byte.2
i2c_lcd_d7 = i2c_lcd_byte.3Key line: i2c_lcd_e = i2c_lcd_byte.4 — shows the default bit mapping for the Ywmjkdz-style adapter used by LCD_IO 12; this is fixed library behaviour, shown here
only for reference, and is separate from the override syntax below.
If you have an I2C LCD display adapter with a different set of connection of the adapter then change this configuration to suit the specific of the adapter as follows. This should be done in the your main program code.
#define i2c_lcd_e i2c_lcd_byte.4 ' <<< overriding the default Enable bit mapping
#define i2c_lcd_rw i2c_lcd_byte.5
#define i2c_lcd_rs i2c_lcd_byte.6
#define i2c_lcd_bl i2c_lcd_byte.7
#define i2c_lcd_d4 i2c_lcd_byte.3
#define i2c_lcd_d5 i2c_lcd_byte.2
#define i2c_lcd_d6 i2c_lcd_byte.1
#define i2c_lcd_d7 i2c_lcd_byte.0Key line: #define i2c_lcd_e i2c_lcd_byte.4 — redefining any of the eight i2c_lcd_* constants in your own program overrides that single bit mapping, so only the bits that differ from the default on your specific
adapter need to be redefined.
See Also:
- LCD_IO 12 — full reference for the LCD_IO 12 connection mode
- LCD_IO 10 — the alternate PCF8574 I2C expander layout
- LCD_IO 10 Port Configuration — the equivalent port-bit override reference for LCD_IO 10
