HELP -unable to display text on 16x2 lcd i2c module. (SOLVED)

hi there. i'm trying display message on lcd_i2c module through nodemcu module.
i able blink backlight of lcd screen when try display text shows nothing. tried adjusting contrast same problem persists. can me cause must ??

code: [select]


#include <liquidcrystal_i2c.h>
#include <streaming.h>

liquidcrystal_i2c lcd(0x3f, 16, 2);

void setup() {

  lcd.begin(16,2);
  lcd.init();
  lcd.backlight();
}

void loop() {
  lcd << "hello" << endl;
}


first of if using nodemcu module in place of arduino (rather in addition it) need download appropriate esp8266 libraries.

you need lcd library can deal both particular i2c module (which have not identified) , esp8266 processor.  i suggest try 'hd44780' library.

also, @ least @ beginning, want deal displaying messages in setup().  leave loop() empty between { , } brackets until things working.

[edit] if powering lcd 3v3 pin on nodemcu board, , if not 3.3v device, may need supply negative voltage @ lcd pin 3 in order see anything.

don

Arduino Forum > Using Arduino > Displays > HELP -unable to display text on 16x2 lcd i2c module. (SOLVED)

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