ESP8266 Community Forum

- Fri Jan 08, 2016 6:38 pm #38250 Currently using the NodeMCU which uses the ESP8266 chip to send data from a sensor to a server, but I also want to see the information through an LCD which is connected to the node MCU, the only thing I found to a tutorial code is from this page
http://thaiopensource.org/%E0%B8%A1%E0%B8%B2%E0%B9%80%E0%B8%A5%E0%B9%88%E0%B8%99-esp8266-%E0%B8%81%E0%B8%B1%E0%B8%9A%E0%B8%88%E0%B8%AD-lcd-%E0%B8%81%E0%B8%B1%E0%B8%99/
Unfortunately I don´t know of that language, so I checked the link to the library and the code provided there, but it tells me there's an invalid connection in the arduino IDE, I think this is caused by the enabler having the same name as the library. Can someone help me confirm this? And if you do, Can you tell me how to fix it?

Code: Select all#include <Wire.h>
#include <LiquidCrystal_I2C.h>

// Set the LCD address to 0x27 for a 16 chars and 2 line display
// Arduino UNO => PIN 4 = SCL, PIN 5 = SDA
// NodeMCU Dev Kit => D1 = SCL, D2 = SDA
#define SCL D3
#define SDA D4
LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup()
{
  // initialize the LCD
  lcd.begin();
  // Turn on the blacklight and print a message.
  lcd.backlight();
  lcd.print("Hello LCD Line 1");
        lcd.setCursor(0, 1);
  lcd.print("Hello LCD Line 2");
        lcd.setCursor(0, 2);
  lcd.print("Hello LCD Line 3");
        lcd.setCursor(0, 3);
  lcd.print("Hello LCD Line 4");
}

void loop()
{
  // Do nothing here...
}

- Sat Jan 09, 2016 10:09 am #38299 Do you have pullup resistors on your I2C bus ?

- Fri Dec 16, 2016 4:18 am #59562 I use module PCF8574, lcd 16x2 and nodemcu 1.0, but it don't run.
Code:
#include <Wire.h> // This library is already built in to the Arduino IDE
#include <LiquidCrystal_I2C.h> //This library you can add via Include Library > Manage Library >
LiquidCrystal_I2C lcd(0x3F, 16, 2);

void setup()
{
lcd.init(); // initializing the LCD
lcd.backlight(); // Enable or Turn On the backlight
lcd.setCursor(0, 0);
lcd.print("SLUMBERJER/MYARDU"); // Start Print text to Line 1
lcd.setCursor(0, 1);
lcd.print("------NODEMCU-----"); // Start Print Test to Line 2
}

void loop()
{
// Nothing Absolutely Nothing!
}

- Fri Dec 16, 2016 9:53 am #59576 check if it is really PCF8574 not PCF8574"A". They differ in i2c address.
Also there are usually jumpers on the board that can change the address.

If in doubt use the i2c scanner (boardsearch).