I. Objectives:
To apply the knowledge in the course microprocessor in order to design a microcontroller based system.
To utilize liquid crystal display as the output of the system.
To create a program for the microcontroller in order to produce the desired output projection.
II. MATERIALS REQUIRED:
2x16 Liquid Crystal Display (LCD)
4x4 keypad
PC – 401
Connector wires
Arduino mini AT328 microcontroller
USB cable
III. BACKGROUND INFORMATION:
IV. PROCEDURE:
Part A. Circuit Connection
1. Connect the LCD pins into the digital pins of the arduino using patching cords following the connection below.
* LCD RS pin to digital pin 12
* LCD Enable pin to digital pin 11
* LCD D4 pin to digital pin 5
* LCD D5 pin to digital pin 4
* LCD D6 pin to digital pin 3 * LCD D7 pin to digital pin 2 * LCD R/W pin to ground * 10K potentiometer - ends to +5V and ground - wiper to LCD VO pin
2. Upload a sample program from the Arduino kit by connecting the USB cable into the pc USB going to Arduino. Through this, the patching compatibility will also be checked.
3. Connect the keypad into the pins of the Arduino having the following specific connection.
*Keypad pin 8 to digital 5
*Keypad pin 1 to digital 4
*Keypad pin 2 to digital 3
*Keypad pin 4 to digital 2
*Keypad pin 3 to digital 9
*Keypad pin 5 to digital 8
*Keypad pin 6 to digital 7
*Keypad pin 7 to digital 6
Part B. Program Construction
1. Run the Arduino software. A window will then appear similar to the one below.
2. Write and upload the program below:
Keypad testing | //to allow the arduino to read the keypad and the LCD#include <Keypad.h>#include <LiquidCrystal.h> // initialize the library with the numbers of the interface pins of the LCDLiquidCrystal lcd(12, 11, 5, 4, 3, 2);//to inculcate the keypad orientation to the arduinoconst byte ROWS = 4; //four rowsconst byte