I am trying to set up an LCD screen without using a resistor or a potentiometer for an Arduino project. This is the LCD I am using: Basic 20x4 Character LCD.

But when I connect to +5V on the Arduino board, my Arduino board turns off. This is how I have the LCD connected to the Arduino on a breadboard.

enter image description here


LCD RS pin to digital pin 12

LCD Enable pin to digital pin 11


• LCD D4 pin to digital pin 5

• LCD D5 pin to digital pin 4

• LCD D6 pin to digital pin 3

• LCD D7 pin to digital pin 2

LCD R/W pin to ground

LCD VSS pin to ground

LCD Cathode pin to ground

LCD Anode pin to digital pin 9

LCD VCC pin to 5V


// include the library code:
include <LiquidCrystal.h>
// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() {
  // set up the LCD's number of columns and rows:
  lcd.begin(20, 4);
  // Print a message to the LCD.
  lcd.print("hello, world!");

void loop() {
  // set the cursor to column 0, line 1
  // (note: line 1 is the second row, since counting begins with 0):
  lcd.setCursor(0, 1);
  // print the number of seconds since reset:
  lcd.print(millis() / 1000);
  • Anode pin always connects with 5V... See my answer diagram. It will helpful. – Hasan Mar 31 '17 at 6:34

Try out this connection. It will helpful.

LCD Connection


Looking at your picture, it seems that you're powering everything through a USB cable. USB 1.x and 2.0 can supply up to to 500 mA AFTER the port is enumerated, otherwise the current is limited to 100 mA.

A quick current consumption budget:

  • LED backlight of your LCD module: typ 240 mA
  • Arduino Mega2560: min 70 mA
  • MIDI shield: some 15-35 mA

That's just 325-350 mA to begin with, and probably higher than that. It's still safely within the 500 mA limit, but as I said some computers will provide 500 mA only after successful enumeration of the device connected to the USB port.

My recommendation for you would be to power your Arduino + MIDI shield + LCD through a wall adapter > 7V. If it works, then the problem is your USB port being unable to supply the required current right from the start.

  • Alright ill try that out. it my not be visible but i also have an Mp3 shield between the Midi shield and arduino – Hjhk90 Mar 31 '17 at 19:08
  • Well, that will add some current consumption as well. You might be already above 500 mA! Under that load, the USB port of the computer shuts himself off for protection. – Enric Blanco Mar 31 '17 at 19:11
  • i think i found the issue one of the pins on the LCD might have been causing a short when i connected to 5v pin .i fixed it and it seems to be working. i did this with the shields on the arduino removed. i will add them back on and see if it works. if it dose not i know the issue is related to the power consumption of the USB. thanks for your help – Hjhk90 Mar 31 '17 at 21:42

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