I recently obtained a handful of used 40×4 (40 characters, 4 rows) LCDs with backlight. These displays are produced by Powertip.

Let’s try to get this Powertip PC4004-A LCD working with Arduino…

Reading the PC4004-A datasheet learns that the pinout is familiar to the popular HD44780 display.

The PC4004-A has the same pin functions but they are assigned to different pins and they are arranged in a 2×8 double row IDC connector with 0.1″ spacing. The backlight has two separate connections on the other end of the PCB. As the HD44780 only supports 2 rows, the PC4004-A has a second Enable pin that addresses character rows 2 and 4.

The display consumes about 4mA, the backlight about 220mA at 4.2V. I really should measure that because these numbers are from the data sheet.

I found some example code on the arduino forum but the sketch failed to compile with Arduino 1.0.3 because it did not find LiquidCrystal440.h. LiquidCristal440.h is actually a rewrite of the LiquidCristal library by John Raines. Extract it and replace the LiquidCrystal library with the new one.

This is my working sample code:

/*
 PC4004-A 40x4 LCD character display - Hello World
 http://code.google.com/p/liquidcrystal440/

  The circuit:
 * LCD RS       pin 11 to arduino digital pin 12
 * LCD R/W      pin 10 to arduino digital pin 11
 * LCD Enable 1 pin 9  to arduino digital pin 10
 * LCD Enable 2 pin 15 to arduino digital pin 9
 * LCD D4       pin 4  to arduino digital pin 5
 * LCD D5       pin 3  to arduino digital pin 4
 * LCD D6       pin 2  to arduino digital pin 3
 * LCD D7       pin 1  to arduino digital pin 2
 * 10K potentiometer:
 * ends to +5V and ground
 * wiper to LCD Vo pin 12

 This example code is in the public domain.
*/

// include the library code
// don't forget to get the modified LiquidCristal library
// by John Raines at http://code.google.com/p/liquidcrystal440/
#include <LiquidCrystal.h>

// LCD function:  RS,RW,EN1,EN2,D4,D5,D6,D7
// PC4004-A pins: 11,10,  9, 15, 4, 3, 2, 1
LiquidCrystal lcd(12,11, 10,  9, 5, 4, 3, 2);

void setup() {
  // set up the LCD's number of columns and rows:
  lcd.begin(40, 4);
  // show some output
  lcd.setCursor(0, 0);
  lcd.print("hello, world!");
  lcd.setCursor(0, 1);
  lcd.print("hello, world 2!");
  lcd.setCursor(0, 2);
  lcd.print("hello, world 3!");
  lcd.setCursor(0, 3);
  lcd.print("hello, world 4!");
}

void loop() {

}

And the photo at the start of this post proves it works!