#include <LiquidCrystal_I2C.h>
#include <Keypad.h>
const uint8_t ROWS = 4;
const uint8_t COLS = 4;
char keys[ROWS][COLS] = {
{ '1', '2', '3', 'A' },
{ '4', '5', '6', 'B' },
{ '7', '8', '9', 'C' },
{ '*', '0', '#', 'D' }
};
char typedChars[8];
char typedbuffer[8];
uint8_t colPins[COLS] = { 9, 8, 7, 6 }; // Pins connected to C1, C2, C3, C4
uint8_t rowPins[ROWS] = { 13, 12, 11, 10 }; // Pins connected to R1, R2, R3, R4
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);
#define I2C_ADDR 0x27
#define LCD_COLUMNS 16
#define LCD_LINES 2
LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);
String typedString = "";
void setup() {
Serial.begin(9600);
lcd.init();
lcd.backlight();
lcd.home();
}
void loop() {
char key = keypad.getKey();
if (key == '0' || key == '1') {
typedString += key;
lcd.print(key);
}
if (key == '#') {
if (typedString.length() == 8) {
typedString.toCharArray(typedbuffer, typedString.length() - 1);
int value = 0;
for (int i = 0; i < 8; i++) // for every character in the string strlen(s) returns the length of a char array
{
value *= 2; // double the result so far
if (typedString[i] == '1') value++; //add 1 if needed
}
Serial.print(typedString);
Serial.print(" is ");
Serial.print(value);
Serial.print(" in digital.");
Serial.println("");
lcd.clear();
lcd.home();
lcd.print(value);
delay(2000);
lcd.clear();
lcd.home();
typedString = "";
} else {
Serial.println("Invalid 8-bit binary value!");
lcd.clear();
lcd.home();
lcd.print("INVALID NUMBER!");
delay(2000);
lcd.clear();
lcd.home();
typedString = "";
}
}
}