PCF8574 I2C LCD backpack driver¶
This driver works with PCF8574 IO expanders. You can see an guide on modifying them and connecting them to LCD screens & I2C here.
"output":
[{
"driver":"pcf8574",
"kwargs":
{
"addr":"0x3f"
}
}]
Note
If you provide backpack’s I2C address as a kwarg, you should pass it as a string (as shown above).
To test your screen, you can just run python output/driver/pcf8574.py
while your screen is connected to I2C bus (you might want to adjust parameters in driver’s if __name__ == "__main__"
section). It will initialize the screen and show some text on it.
-
class
output.drivers.pcf8574.
Screen
(bus=1, addr=39, debug=False, **kwargs)[source]¶ A driver for PCF8574-based I2C LCD backpacks.
-
__init__
(bus=1, addr=39, debug=False, **kwargs)[source]¶ Initialises the
Screen
object.Kwargs:
bus
: I2C bus number.addr
: I2C address of the board.debug
: enables printing out LCD commands.**kwargs
: all the other arguments, get passed further to HD44780 constructor
-
write_byte
(data, char_mode=False)[source]¶ Takes a byte and sends the high nibble, then the low nibble (as per HD44780 doc). Passes
char_mode
toself.write4bits
.
-