Hello Ian,
Thanks for the tutorial. Downloaded the library and installed it, copied your sketch and made the modification to fit my SainSmart 20x4, checked the address and it is 0x3F. I followed every detail but keep getting the following error when compiling:
SainSmart4x20LCD.cpp.o: In function __static_initialization_and_destruction_0': C:\Program Files\Arduino/SainSmart4x20LCD.ino:34: undefined reference to LiquidCrystal_I2C::LiquidCrystal_I2C(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char)'
SainSmart4x20LCD.cpp.o: In function loop': C:\Program Files\Arduino/SainSmart4x20LCD.ino:54: undefined reference to LiquidCrystal_I2C::setBacklight(unsigned char)'
C:\Program Files\Arduino/SainSmart4x20LCD.ino:56: undefined reference to LiquidCrystal_I2C::setBacklight(unsigned char)' SainSmart4x20LCD.cpp.o: In function setup':
C:\Program Files\Arduino/SainSmart4x20LCD.ino:38: undefined reference to LiquidCrystal_I2C::begin(unsigned char, unsigned char, unsigned char)' C:\Program Files\Arduino/SainSmart4x20LCD.ino:42: undefined reference to LiquidCrystal_I2C::setBacklightPin(unsigned char, t_backlighPol)'
C:\Program Files\Arduino/SainSmart4x20LCD.ino:43: undefined reference to `LiquidCrystal_I2C::setBacklight(unsigned char)'
I don't know what I am doing wrong. Have you encountered this before or can you decipher the problem from the compiler errors?
Many thanks,
Al