[SOLVED] I2C LCD - Setup instructions for 16x2

rpt007:
Ok, this old thread is not easy to kill ... -> shows that a key instruction how to set up LCD displays might be needed to avoid most newbie mistakes.

Very short shots:

  • Good, solid soldering is key
  • wiring the right pins from Arduino to display is key
  • using a library with a suitable constructor is key (libraries/constructors are in most cases not exchangeable)
  • when using a I2C interface - make sure you got the right I2C address (e.g. use a I2C scanner to identify the address)
  • have a look at how the backlight is factorized (do you need an external resistor or not to adjust the current consumption for the backlight?)
  • did you connect Vcc and GND to the display?
  • does the simple "Hello World" example sketch work on your display?
  • slowly turn the contrast potentiometer from one extreme to the other and watch your screen; stop turning when the desired output is shown
  • for your own sketch: check first (that's why some people call it "debugging mode"), if your desired text or numeric output is displayed in the serial monitor and only if that works, convert/direct the output to the LCD display (having succeeded before with the "Hello World" simple sketch on your LCD screen)

Maybe I forgot some more tipps, but those above were the ones which helped me to convince my LCD displays to show me some output :slight_smile:

Hello,

thank you for all the tips here.

I've done all the check above, but the LCD still doesn't work.

The lcd turns on (not not full luminosity) and it flashes.

I followed this tutorial (https://www.arduino.cc/en/Tutorial/HelloWorld)

COuld anyone help, me please?