IIC/I2C 1602 LCD Blue Screen With adapter

The module uses PCF8574, which allows most MCUs to achieve remote 1/00 expansion through two bidirectional buses (12C). The device contains an 8-bit quasi-bidirectional port and an I2C bus connected to 0. PCF8574 current consumption is very low, and the port output latch has a large current drive capability, which can directly drive LEDs. It also has an interrupt wiring (INT open-drain output) that can be connected to the MCU’s interrupt logic. By sending an interrupt signal through INT, the remote |/0 port can notify the MCU whether there is data input from the port without passing through the 12C bus communication.
 
Use note:
Due to the different batches of the manufacturer, the PCF8574 version on the board may also be different for this module. There are currently PCF8574T and PCFB574AT versions with the same pin functions but different I2C device addresses. When the module is available, first check the chip model, and then modify the I2C ID number in the program. Be sure to read the description below.
 
Product details:
Size: 41.mm(length)*19mm(width)*15.3mm(height)
Working voltage: 2.5-6V

Pin description:
The rightmost plug of the module corresponds to the first pin of the LCD,
GND system power ground,
VCC system power supply+,
SDA data cable,
SCL clock line.
 
Instructions for use:
With backlight power control, you can set whether to connect the backlight power through the jumper cap. Plug in the jumper cap to connect the backlight power, unplug the jumper cap to disconnect the backlight power. The contrast can be adjusted by rotating the blue potentiometer. Clockwise increase, counterclockwise decrease. Modules can be cascaded, up to 8 can be cascaded. Modify the device address by shorting the A0/A1/A2 pads on the module.
 
Default address: When shipping, A2~A0 are all vacant. The I2C address at this time is the default address in the table below. If you want to modify the address yourself, pay attention to the floating address pad is 1 and the short circuit is 0.
 
Chip version:
 
PCF8574T:
IC address (high order first) 0100 A2 A1 A0 R/W
Default 7-bit address (no read/write direction bit): 0100 111 (0x27)
The default 8-bit address (including read and write direction bits): write: 0100 1110 (0x4E) read: 0100 1111 (0x4F)
 
PCF8574AT:
IC address (high order first) 0111 A2 A1 A0 R/W
Default 7-bit address (no read/write direction bit): 0111 111 (0x3F)
The default 8-bit address (including the read and write direction bits): Write: 0111 1110 (0x7E) Read: 0111 1111 (0x7F)