#include <EEPROM.h>
#include <Wire.h>
#include <hd44780.h> // main hd44780 header
#include <hd44780ioClass/hd44780_I2Cexp.h> // i2c expander i/o class header
hd44780_I2Cexp lcd; // declare lcd object: auto locate & config exapander chip
// LCD geometry
const int LCD_COLS = 16;
const int LCD_ROWS = 2;
#include <Keypad.h>
const byte ROWS = 4; //four rows
const byte COLS = 4; //three columns
char keys[ROWS][COLS] =
{
{'1', '2', '3', 'A'},
{'4', '5', '6', 'B'},
{'7', '8', '9', 'C'},
{'*', '0', '#', 'D'}
};
byte rowPins[ROWS] = {6, 7, 8, 9}; //connect to the row pinouts of the keypad
byte colPins[COLS] = {5, 4, 12, 11}; //connect to the column pinouts of the keypad
Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );
bool a = true;
unsigned long count;
void setup()
{
Serial.begin(115200);
lcd.begin(LCD_COLS, LCD_ROWS);
lcd.setCursor(3, 0);
lcd.print(" PRIYA");
lcd.setCursor(3, 1);
lcd.print("ELECTRONICS");
delay(100);
for (int positionCounter = 0; positionCounter < 40; positionCounter++)
{
lcd.scrollDisplayLeft();
delay(120);
}
delay(800);
lcd.clear();
lcd.setCursor(0, 0);
lcd.print("Set Count:");
lcd.setCursor(11, 0);
lcd.print(EEPROM.get(0, count)); // <<<<<<<<< read from EEPROM here
}
void loop()
{
const byte entryMaxSize = 5;
static char digits[entryMaxSize + 1];
static byte x; // index
char key = keypad.getKey();
if (key != NO_KEY) // Check for a valid key.
{
switch (key)
{
case 'A':
lcd.clear();
lcd.setCursor(0, 0);
lcd.print("Set Count:");
lcd.setCursor(11, 0);
lcd.print(EEPROM.get(0, count)); // <<<<<<<<< read from EEPROM here
x = 0; // reset the counter
a = true;
break;
case 'D':
if (a)
{
if (x == 0)
{
invalidCount();
}
else
{
lcd.clear();
lcd.print("Count Set:");
for (byte i = 0; i < x; i++)
{
lcd.print(digits[i]);
a = false;
}
count = atol(digits);
EEPROM.put(0, count); // <<<<<<<<< save to EEPROM here
Serial.print(count);
}
}
break;
default:
if (a)
{
// if not 5 characters yet
if (x < entryMaxSize)
{
// add key to userinput array and increment counter
if ( key >= '0' && key <= '9' ) // key is of type char and has a value between 0 and 9 so do something with it.
{
digits[x++] = key;
digits[x] = '\0';
lcd.print( key ) ; // new print statement <<<<<<<<<<<<<<<<
}
}
else
{
countWarning();
}
}
break;
}
}
}
void invalidCount()
{
lcd.clear();
lcd.setCursor(0, 0);
lcd.print("Invalid Count!!");
lcd.setCursor(0, 1);
lcd.print("Press A"); // suggesting the user to enter the count again
a = false;
}
void countWarning()
{
lcd.clear();
lcd.setCursor(0, 0);
lcd.print("5 Digits Only!!"); // warning for the user if more than permitted digits are entered
lcd.setCursor(0, 1);
lcd.print("Press A"); // suggesting the user to enter the count again
a = false;
}
On power on, set count shows the number that was saved last time. On pressing 'A' to set a new count it shows Set Count: whatever number was stored at the latest. If a three digit number was stored it shows Set Count: xxx and if I try to enter a new number, instead of replacing those digits it lets me print in the remaining places. For example if the new number to be entered is 666, then Set Count: xxx66. Only on pressing the enter key 'D' I am able to view the set count.