PIC Development Board - Hex Keypad

sbit X_1 at RB0_bit;

sbit X_2 at RB1_bit;

sbit X_3 at RB2_bit;

sbit X_4 at RB3_bit;

sbit Y_1 at RB4_bit;

sbit Y_2 at RB5_bit;

sbit Y_3 at RB6_bit;

sbit Y_4 at RB7_bit;

#define Keypad_PORT PORTB

#define Keypad_PORT_Direction TRISB

// LCD module connections

sbit LCD_RS at RD0_bit;

sbit LCD_EN at RD1_bit;

sbit LCD_D4 at RD4_bit;

sbit LCD_D5 at RD5_bit;

sbit LCD_D6 at RD6_bit;

sbit LCD_D7 at RD7_bit;

sbit LCD_RS_Direction at TRISD0_bit;

sbit LCD_EN_Direction at TRISD1_bit;

sbit LCD_D4_Direction at TRISD4_bit;

sbit LCD_D5_Direction at TRISD5_bit;

sbit LCD_D6_Direction at TRISD6_bit;

sbit LCD_D7_Direction at TRISD7_bit;

// End LCD module connections

char keypad_scanner(void)

{

X_1 = 0; X_2 = 1; X_3 = 1; X_4 = 1;

if (Y_1 == 0) { delay_ms(100); while (Y_1==0); return '1'; }

if (Y_2 == 0) { delay_ms(100); while (Y_2==0); return '2'; }

if (Y_3 == 0) { delay_ms(100); while (Y_3==0); return '3'; }

if (Y_4 == 0) { delay_ms(100); while (Y_4==0); return '4'; }

X_1 = 1; X_2 = 0; X_3 = 1; X_4 = 1;

if (Y_1 == 0) { delay_ms(100); while (Y_1==0); return '4'; }

if (Y_2 == 0) { delay_ms(100); while (Y_2==0); return '5'; }

if (Y_3 == 0) { delay_ms(100); while (Y_3==0); return '6'; }

if (Y_4 == 0) { delay_ms(100); while (Y_4==0); return '8'; }

X_1 = 1; X_2 = 1; X_3 = 0; X_4 = 1;

if (Y_1 == 0) { delay_ms(100); while (Y_1==0); return '7'; }

if (Y_2 == 0) { delay_ms(100); while (Y_2==0); return '8'; }

if (Y_3 == 0) { delay_ms(100); while (Y_3==0); return 'A'; }

if (Y_4 == 0) { delay_ms(100); while (Y_4==0); return 'B'; }

X_1 = 1; X_2 = 1; X_3 = 1; X_4 = 0;

if (Y_1 == 0) { delay_ms(100); while (Y_1==0); return 'C'; }

if (Y_2 == 0) { delay_ms(100); while (Y_2==0); return 'D'; }

if (Y_3 == 0) { delay_ms(100); while (Y_3==0); return 'E'; }

if (Y_4 == 0) { delay_ms(100); while (Y_4==0); return 'F'; }

return 'n';

}

char switch_press_scan(void) // Get key from user

{

char key = 'n'; // Assume no key pressed

while(key=='n') // Wait untill a key is pressed

key = keypad_scanner(); // Scan the keys again and again

return key; //when key pressed then return its value

}

void InitKeypad(void)

{

Keypad_PORT = 0x00; // Set Keypad port pin values zero

Keypad_PORT_Direction = 0xF0; // Last 4 pins input, First 4 pins output

OPTION_REG &= 0x7F;

}

char Key;

void main()

{

Lcd_Init(); // Initialize LCD

Lcd_Cmd(_LCD_CLEAR);

InitKeypad();

while(1)

{

Key = switch_press_scan();

Lcd_Chr_Cp(Key);

}

}