So I just grabbed a large 20x4 LCD screen off of Amazon that is supposed to compatible with arduino (LCD Module for Arduino 20 x 4, White on Blue). With very few snags I was up an running in no time actually…

Things to note: This only requires the use the 5v power provided by the Arduino Uno and 2 analog pins. This guy on the arduino forums wrote up an amazing walk-through that I highly suggest you read.

Things you may want to know from me:

1. Yes, I did have to bend the pins.
2. It is really bright!
3. The scanner program detected the IC2 device at 0x27 for me.
4. When I copied the library over into my library directories it did not import it automatically. So when I went to run the test program it would not compile! I had to go to “Sketch” -> “Import Library” and pick it out…
5. here is another example test program that worked with the exact model from Amazon listed above (ordered 7/23/13)…

{% highlight cpp %}

#include #include #include #include #include #include #include #include

/* ** Example Arduino sketch for SainSmart I2C LCD2004 adapter for HD44780 LCD screens ** Readily found on eBay or http://www.sainsmart.com/ ** The LCD2004 module appears to be identical to one marketed by YwRobot ** ** Address pins 0,1 & 2 are all permenantly tied high so the address is fixed at 0x27 ** ** Written for and tested with Arduino 1.0 ** This example uses F Malpartida’s NewLiquidCrystal library. Obtain from: ** https://bitbucket.org/fmalpartida/new-liquidcrystal ** ** Edward Comer ** LICENSE: GNU General Public License, version 3 (GPL-3.0) ** ** NOTE: TEsted on Arduino NANO whose I2C pins are A4==SDA, A5==SCL */ #include #include #include

#define I2C_ADDR 0x27 // Define I2C Address where the PCF8574A is #define BACKLIGHT_PIN 3 #define En_pin 2 #define Rw_pin 1 #define Rs_pin 0 #define D4_pin 4 #define D5_pin 5 #define D6_pin 6 #define D7_pin 7

int n = 1;

LiquidCrystal_I2C lcd(I2C_ADDR,En_pin,Rw_pin,Rs_pin,D4_pin,D5_pin,D6_pin,D7_pin);

void setup() { lcd.begin (20,4);

// Switch on the backlight lcd.setBacklightPin(BACKLIGHT_PIN,POSITIVE); lcd.setBacklight(HIGH); lcd.home (); // go home

lcd.print(“Yay First Line!”);
lcd.setCursor ( 0, 1 ); // go to the 2nd line lcd.print(“What happens if we write past the end of the line?”); lcd.setCursor ( 0, 2 ); // go to the third line lcd.print(“LCDs are cool”); lcd.setCursor ( 0, 3 ); // go to the fourth line lcd.print(“Iteration No: ”); }

void loop() { lcd.setCursor (14,3); // go col 14 of line 3 lcd.print(n++,DEC); lcd.setBacklight(HIGH); // Backlight on delay(3000); }

{% endhighlight %}