The I2C Module features an integrated PCF8574 I2C chip that converts serial I2C data into parallel data for the LCD display.
These modules are typically provided with a default I2C address of either 0x27 or 0x3F. To identify your module, check the black I2C adapter board on the underside. If it has three sets of pads labeled A0, A1, and A2, the default address is 0x3F. If no pads are present, the default address is 0x27.
The module also includes a contrast adjustment pot located on the underside of the display. This may need to be adjusted for optimal text visibility.
