I'am just trying to learn the Arduion together with an LCD with I2C bus. (LCD see http://www.robot-electronics.co.uk/htm/Lcd03tech.htm
). I use the Arduino Wire library rather than any LCD library just to learn what's going on "behind the scene".
Anyhow, I have seen that I (always?) need to use "Wire.send(0x00)" before any command e.g. Wire.send(0x13). For example to switch on the backlight I need to do this;
Wire.beginTransmission(0x63); // The 7 bit LCD adress is 0x63
Wire.send(0x00); // Why is this row needed?
Wire.send(0x13); // Backlight on
Why do I need to send "0x00" first?