Smart Home Automation Forum

Hi, i just bought KS868-A16 Rev1.6 and i have problems connecting a serial LCD.

Port connected P19
LCD-serial controller PC8574T
LCD model 20x4

Testet whith 3,3V also whith 5V
Scan whith Arduino i2c scanner no results.

LCD tested on Arduino Uno is ok.
KC868-A16 tested whith a simplet test IO ok.
Try whith simple Arduino examples i2c LCD
Try wired the LCD examples SCL/SDA to IO 4/5
Any help please?

you need to check your serial LCD RXD and TXD voltage level, 3.3v or 5v?
you using serial LCD, how to check with i2c scan???

“you using serial LCD, how to check with i2c scan???”

i don’t understand ,serial LCD use i2c, and yes i2c scan need to see LCD i2c controller.

i don't understand you. why serial LCD will use i2c??? take a photo, how you wire and your LCD.

I use PCF8574 I/O-I2C for LCD(i use whith Arduino whith no problem)

Attached are a pic whith adapter/driver for LCD.

don't use serial LCD for PCF7574 GPIO, you should connect them with ESP32's pin directly.

Ok, so need to solder I2C LCD to 21/22 Pin of ESP32?

A16 board already have I2C extender on PCB.
i really don't understand your question. you said your LCD is serial, now you said it's I2C LCD?