LCD Keypad Shield wiring and control #18307
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Hi Daniel, |
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I have the same LCD KeyPad shield but put it aside because of 5V logic level and the 8 Bit Interface which is as far as I remember an 8080 type 8 bit parallel data bus and if so will not easly work by using a port expander. |
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Hi,
I'm trying to write a simple code to display text in a LCD screen using en ESP32.
First, I bought a LCD display with an I2C interface. I used the code on this library and it worked like a charm. Particularly, these scripts esp8266_i2c_lcd.py and esp8266_i2c_lcd_test.py.
Then, I moved to the LCD KeyPad shield in the image:
As this shield comes without an I2C interface, I bought a PCF8574 module for the code to work exactly in the same way. However, when running the code, the LCD screen remains unchanged (white squared over the blue screen as in the image).
When I scan the I2C bus, the ESP32 detects the PCF8574 address correctly and uses this address to instanciate the LCD class.
My wiring:
PCF8574 SCL -> ESP32 Pin 22
PCF8574 SDA -> ESP32 Pin 21
PCF8574 GND -> Common GND on a breadboad
PCF8574 VCC -> I tried common 5V on a breadboad and 3.3V on the ESP32
PCF8574 P0 -> LCD RS
PCF8574 P2 -> LCD E
PCF8574 P4 -> LCD D4
PCF8574 P5 -> LCD D5
PCF8574 P6 -> LCD D6
PCF8574 P7 -> LCD D7
LCD VCC -> Common 5V on a breadboad
LCD GND -> Common GND on a breadboad
This is the pinout I'm following:
Thanks!
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