Displaying information is one of the crucial steps in electronic projects. So using LCDs has always been one of the most popular ways to display information. This 1602 LCD Keypad shield is a very popular display specifically for Arduino. 16*2 LCD module consists of 16 columns and 2 rows, so it has 32 (16*2) characters in total. Each character has 40pixels (5*8) and thus for 32 characters there 1280 pixels (32*40). An interface IC HD447480 attached to the backside of the LCD module to determine the position of the pixel. This IC gets commands and data from the microcontroller and processes it, thus display it on the screen. The onboard potentiometer used for screen contrast adjustment.
This 2×16 LCD Keypad shield comes with 6 momentary push buttons for menu navigation. In which 5 are connected with A0 analog input through a resistor to give different voltage for each button and saving on input/output pins. Hence also known as Navigation sheild. Pins 4, 5, 6, 7, 8, 9, and 10 are used to interface with the LCD. The onboard LED indicates power-on status. This LCD shield is suitable for Arduino UNO, MEGA, Leonardo, and other microcontrollers. And is fully compatible with the Arduino 4-bit “LiquidCrystal” library.
Moreover, in this shield, all 4 keys connected to the analog pin 0 to save on digital pins. So an ADC used to read them. When a key pressed, it returns a value to the A0 pin according to the internal resistive splitting circuit, which identifies the type of the key. It is quite simple to work with these LCD s and they have full compatibility with all microcontrollers and processor boards.