KC868-A16 LCD issue

[dany_l2003]

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?

[admin]

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???

[dany_l2003]

“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.

[admin]

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

[dany_l2003]

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

Attached are a pic whith adapter/driver for LCD.

[admin]

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

[dany_l2003]

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

[admin]

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?

[zegikniet]

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?

This is a standard LCD, the 20x4
It has a 8574 on board to be able to use it as a I2C device.
i2C is serial data.

I2C Adres: 0x20-0x27 (0x20 standard)

https://www.instructables.com/How-to-Use...Backlight/