// Define the keypad layout
char key[3][3] = {{'1', '2', '3'}, {'4', '5', '6'}, {'7', '8', '9'}};
// Define output pins for columns
#define pin1 8
#define pin2 9
#define pin3 10
// Define input pins for rows
#define pin5 2
#define pin6 3
#define pin7 4
// Define input and output pins for keypad
int input_pins[3] = {2, 3, 4};
int output_pins[3] = {8, 9, 10};
// Variables to store key press and digit
char Pressed;
char digit;
// Segment pin definitions for 7-segment display
#define A 5
#define B 6
#define C 7
#define D 11
#define E 12
#define F 13
#define G A0
// Setup function, executed once on startup
void setup() {
// Initialize serial communication
Serial.begin(9600);
// Set up pins for keypad columns and rows
for (int i = 0; i < 3; i++) {
pinMode(output_pins[i], OUTPUT);
digitalWrite(output_pins[i], HIGH);
pinMode(input_pins[i], INPUT_PULLUP);
}
// Set up pins for 7-segment display segments
pinMode(A, OUTPUT);
pinMode(B, OUTPUT);
pinMode(C, OUTPUT);
pinMode(D, OUTPUT);
pinMode(E, OUTPUT);
pinMode(F, OUTPUT);
pinMode(G, OUTPUT);
// Turn off all segments initially
digitalWrite(A, LOW);
digitalWrite(B, LOW);
digitalWrite(C, LOW);
digitalWrite(D, LOW);
digitalWrite(E, LOW);
digitalWrite(F, LOW);
digitalWrite(G, LOW);
}
// Function to detect keypad key press
char mykey(void) {
int r, c;
for (r = 0; r < 3; r++) {
digitalWrite(output_pins[r], LOW);
for (c = 0; c < 3; c++) {
if (digitalRead(input_pins[c]) == LOW) {
// Print debug information for button press detection
Serial.print("Button pressed at row ");
Serial.print(r);
Serial.print(", column ");
Serial.println(c);
// Debounce by waiting for a short time
delay(50);
if (digitalRead(input_pins[c]) == LOW) {
while (digitalRead(input_pins[c]) == LOW) {
// Wait until the button is released
}
// Reset the row output and return the pressed key
digitalWrite(output_pins[r], HIGH);
return key[r][c];
}
}
}
// Reset the row output
digitalWrite(output_pins[r], HIGH);
}
return '$'; // Return special character for no key press
}
// Main loop function
void loop() {
Pressed = mykey(); // Call mykey function to get pressed key
if (Pressed != '$') {
// Display logic using segment pins
switch (Pressed) {
// Define segment pin states for each digit
case '1':
digitalWrite(A, HIGH);
digitalWrite(B, LOW);
digitalWrite(C, LOW);
digitalWrite(D, HIGH);
digitalWrite(E, HIGH);
digitalWrite(F, HIGH);
digitalWrite(G, HIGH);
break;
case '2':
digitalWrite(A, LOW);
digitalWrite(B, LOW);
digitalWrite(C, HIGH);
digitalWrite(D, LOW);
digitalWrite(E, LOW);
digitalWrite(F, HIGH);
digitalWrite(G, LOW);
break;
case '3':
digitalWrite(A, LOW);
digitalWrite(B, LOW);
digitalWrite(C, LOW);
digitalWrite(D, LOW);
digitalWrite(E, HIGH);
digitalWrite(F, HIGH);
digitalWrite(G, LOW);
break;
// Define cases for other digits
default:
// Turn off all segments for unhandled cases
digitalWrite(A, LOW);
digitalWrite(B, LOW);
digitalWrite(C, LOW);
digitalWrite(D, LOW);
digitalWrite(E, LOW);
digitalWrite(F, LOW);
digitalWrite(G, LOW);
break;
}
// Add delay to control display refresh rate
delay(100);
}
}