Johnny Five LCD: black boxes only I posted this also at Stack Overflow. I have tested the Johnny Five LED example on my Arduino Uno, and it worked fine. Now I need to test Johnny Five LCD. I connected all wires correctly.



The code:

var five = require("johnny-five"), board, lcd;

board = new five.Board();
board.on("ready", function() {
  lcd = new five.LCD({
    // LCD pin name  RS  EN  DB4 DB5 DB6 DB7
    // Arduino pin # 7    8   9   10  11  12
    pins: [7, 8, 9, 10, 11, 12],
    backlight: 6,
    rows: 2,
    cols: 20
    // Options:
    // bitMode: 4 or 8, defaults to 4
    // lines: number of lines, defaults to 2
    // dots: matrix dimensions, defaults to "5x8"
  });

  // Tell the LCD you will use these characters:
  lcd.useChar("check");
  lcd.useChar("heart");
  lcd.useChar("duck");

  // Line 1: Hi rmurphey &amp; hgstrp!
  lcd.clear().print("rmurphey, hgstrp");
  lcd.cursor(1, 0);

  // Line 2: I &lt;3 johnny-five
  // lcd.print("I").write(7).print(" johnny-five");
  // can now be written as:
  lcd.print("I :heart: johnny-five");

  this.wait(3000, function() {
    lcd.clear().cursor(0, 0).print("I :check::heart: 2 :duck: :)");
  });

  this.repl.inject({
    lcd: lcd
  });
});


But it doesn't output as expected. It is showing one row of black boxes only. what have I missed?
Try changing the resistance in your 10k potentiometer. This might be a reason for the black boxes. 

P.S: I.m a beginner too.