Arduino LCD1602 character LCD expansion board the motherboard with a new high-quality 2-line 16 character LCD not only has the contrast adjustment knob backlight selector switch also has four directional buttons a select button and a reset button; This extension 1602 simplify the circuit board in the true sense this plug directly to the Arduino Duemilanove controller board. The module is blue backlight with white words. This is a basic 16 character by 2 line white-on-green display. Module debugging: The LCD Keypad Shield plugged into the Arduino controller then you need to download LCD4Bit_mod.h (Right Save As) library files to arduino-0015 hardware libraries and then compile the following test program and then downloaded to the Arduino the initial use LCD Keypad Shield the first observation there is no LCD display character if there is no contrast display characters that may be incorrect you can use a flathead screwdriver to adjust RP1 (clockwise rotation) the characters can be transferred to emerge clearly.