Details and Connections of I2C LCD Adapter
DESCRIPTION
I2C lcd adapter is a device containing a micro-controller PCF8574 chip. This micro-controller is a I/O expander, which communicates with other micro-controller chip with two wire communication protocol. Using this adapter anyone can control an 16x2 LCD with only two wire(SDA, SCL). It saves many pins of arduino or other micro-controller. It has an built in potentiometer for control lcd contrast. The default I2C address is 0x27. You can change this address by connecting A0, A1, A2.
A0 A1 A2 Address 0 0 0 0x20 0 0 1 0x21 0 1 0 0x22 0 1 1 0x23 1 0 0 0x24 1 0 1 0x25 1 1 0 0x26 1 1 1 0x27
0 => LOW
1 => HIGH
First, you have to solder this adapter with lcd. You can directly connect it to the lcd display backside. But i have solder it on a pcb. You can also make it as you wish. But you must be careful about the right connection. Otherwise you will face a great problem.
Arduino => I2C LCD adapter
GND => GND
5V => VCC
A4 => SDA
A5 => SCL
#define USE_ALB_LCD_I2C
#include "ArduinoLearningBoard.h"
ALB_LCD_I2C lcd;
void setup() {
lcd.init();
lcd.backlight();
lcd.clear();
}
void loop() {
lcd.setCursor(0,0);//lcd.setCursor(coloumn, row);
lcd.print("ABCD 1234 +-/*");
lcd.setCursor(0,1);//here row=1 means second line
lcd.print((char)64);//64 = @
lcd.print((char)223);//223 = dgree sign
lcd.print((char)224);//224 = alpha sign
lcd.print((char)232);//232 = root
lcd.print((char)242);//242 = thita
lcd.print((char)228);//228 = micro
}
open arduino IDE => go to Tools => manage libraries => search for Arduino Learning Board
and download the library.
If you already have the library then skip this step.
I have use the I2C lcd to show the tempareture and humidity of the environment.