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User avatar
By Luxfire
#82805 Hello Guys,
i cant show anything on lcd by i2c. my conections: SCL -->D1 SDA -->D2 .
There is some data flow between nodemcu and lcd, i've checked it with osciloscope. nodemcu also can dim the backlight of lcd and turn it on again, so i think it works? but i can't achieve showing any text. also contrast was checked with multimeter if the potentiometer works. Have You some ideas what could have gone wrong?
Code: Select all#include <LiquidCrystal_I2C.h>
#include <Wire.h>
LiquidCrystal_I2C lcd(0x27, 20, 4);
void setup() {
//Use predefined PINS consts
lcd.print("Hello, NodeMCU");

void loop() { // do nothing here
User avatar
By Luxfire
#82842 i've got PCF8574T chip on LCD. Before this code i also uploaded i2c scanner, also if i change address from 0x27 to 0x17(just random address) lcd backlight won't off/on anymore. so i'm sure(?) that 0x27 is my lcd address.
User avatar
By QuickFix
#82882 Just a wild idea: have you verified that the LCD-library you're using is ESP8266 compatible?

Not all (in fact most) libraries for hardware is written with the Arduino (ATMEGA) in mind and are not 100% compatible with the NodeMCU (ESP8266).