I2c display

Hi, i bought a lcd i2c display but it is not working on my nodemcu. I am getting a stupid error. :confused:

Can anybody help me out?

You are mixing up different & multiple libraries. The headers you are including are from a different library than the code in your sketch.

You need to pick one library and then use the proper constructor for that library.

fm's LiquidCrystal replacement library which has header files by the names you are including does not use The constructor for that library requires that you tell the library the PCF8574 pin mappings in the constructor.

The IDE bundled library (which is what your code appears to be trying to use) has hard coded PCF8574 pin mappings. The pin mappings used by that library may or may not work with your backpack. That library uses init() rather than begin() to initialize the library and lcd.

Alternately you can try my hd44780 library which is available in the IDE library manager. You can read more about it here: https://github.com/duinoWitchery/hd44780 It will runtime auto-detect the i2c address and the pin mappings.

There are some in-progress updates for ESP devices which will fix a few issues in the I2CexpDiag sketch but it should work to get you up and going with normal sketch code.

--- bill