/* ** 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) */ #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("SainSmart I2C test"); lcd.setCursor ( 0, 1 ); // go to the next line lcd.print("F Malpartida library"); lcd.setCursor ( 0, 2 ); // go to the next line lcd.print("Test By Edward Comer"); lcd.setCursor ( 0, 3 ); // go to the next line lcd.print("Iteration No: "); } void loop() { // Backlight on/off every 3 seconds lcd.setCursor (14,3); // go col 14 of line 3 lcd.print(n++,DEC); lcd.setBacklight(LOW); // Backlight off delay(3000); lcd.setBacklight(HIGH); // Backlight on delay(3000); }