425 lines
11 KiB
C
425 lines
11 KiB
C
#include <LPC17xx.h>
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/* PORT MAPPING:
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* KEYPAD MATRIX (4x4):
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* Columns: P0.15 - P0.18 (Output, pulled high, scan low)
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* Rows: P0.19 - P0.22 (Input, pulled high internally)
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*
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* Layout: 0 1 2 3
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* 4 5 6 7
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* 8 9 A B
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* C D E F
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*
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* 7-SEGMENT DISPLAY:
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* Segments: P0.4 - P0.11 (a-g + dp)
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* Digit Enable: P1.23 (active high)
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*
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* LCD (16x2):
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* Data: P0.23 - P0.26 (D4-D7, 4-bit mode)
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* RS: P0.27
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* EN: P0.28
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*
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* MODE BUTTON:
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* P2.12 (Input, internal pull-up)
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*
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* KEY FUNCTIONS:
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* 0-9, A-F: Digit input (valid based on current base)
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*
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* OPERATOR MODE (Hold Key 0 + another key):
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* Key 0 + B: Addition (+)
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* Key 0 + C: Clear (C)
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* Key 0 + D: Subtraction (-)
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* Key 0 + E: Multiplication (*)
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* Key 0 + F: Equals (=)
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*
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* P2.12 Button: Mode selection (cycles: DEC->BIN->OCT->HEX)
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*/
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// 7-Segment patterns
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const unsigned char seven_seg[16] = {
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0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07,
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0x7F,0x6F,0x77,0x7C,0x39,0x5E,0x79,0x71
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};
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// Keypad defines
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#define COL_BASE 15
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#define ROW_BASE 19
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#define COL_MASK (0x0F << COL_BASE)
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#define ROW_MASK (0x0F << ROW_BASE)
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// 7-Segment defines
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#define SEG_SHIFT 4
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#define DIGIT_EN (1<<23)
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// LCD defines
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#define LCD_DATA_SHIFT 23
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#define LCD_DATA_MASK (0x0F << LCD_DATA_SHIFT)
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#define LCD_RS (1<<27)
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#define LCD_EN (1<<28)
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// Mode button defines
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#define MODE_BUTTON (1<<12)
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// Calculator states
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#define MODE_BIN 2
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#define MODE_OCT 8
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#define MODE_DEC 10
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#define MODE_HEX 16
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#define OP_NONE 0
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#define OP_ADD 1
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#define OP_SUB 2
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#define OP_MUL 3
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// Global variables - CHANGED to signed int
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int input_num = 0;
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int stored_num = 0;
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int result = 0;
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unsigned int current_base = MODE_DEC;
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unsigned int operation = OP_NONE;
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unsigned char lcd_flag = 0;
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void delay(volatile unsigned int d){
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while(d--) __NOP();
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}
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void lcd_delay(unsigned long r){
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unsigned long i;
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for(i=0; i<r; i++);
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}
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void lcd_write_nibble(unsigned char nibble, unsigned char is_data){
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unsigned long temp;
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temp = (nibble & 0x0F) << LCD_DATA_SHIFT;
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LPC_GPIO0->FIOPIN = (LPC_GPIO0->FIOPIN & ~LCD_DATA_MASK) | temp;
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if(is_data)
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LPC_GPIO0->FIOSET = LCD_RS;
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else
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LPC_GPIO0->FIOCLR = LCD_RS;
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LPC_GPIO0->FIOSET = LCD_EN;
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lcd_delay(100);
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LPC_GPIO0->FIOCLR = LCD_EN;
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lcd_delay(500000);
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}
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void lcd_cmd(unsigned char cmd){
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lcd_write_nibble(cmd >> 4, 0);
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lcd_write_nibble(cmd, 0);
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}
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void lcd_data(unsigned char data){
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lcd_write_nibble(data >> 4, 1);
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lcd_write_nibble(data, 1);
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}
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void lcd_init(void){
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lcd_delay(5000000);
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lcd_write_nibble(0x03, 0);
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lcd_delay(500000);
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lcd_write_nibble(0x03, 0);
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lcd_delay(500000);
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lcd_write_nibble(0x03, 0);
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lcd_delay(500000);
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lcd_write_nibble(0x02, 0);
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lcd_delay(500000);
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lcd_cmd(0x28);
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lcd_cmd(0x0C);
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lcd_cmd(0x01);
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lcd_delay(500000);
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lcd_cmd(0x06);
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}
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void lcd_print_str(const char* str){
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while(*str){
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lcd_data(*str++);
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}
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}
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// MODIFIED to handle negative numbers
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void lcd_print_num(int num, unsigned int base){
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char buffer[17];
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int i = 0;
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// For non-decimal bases, show as unsigned (two's complement representation)
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if(base != MODE_DEC){
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unsigned int unum = (unsigned int)num;
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if(unum == 0){
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lcd_data('0');
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return;
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}
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while(unum > 0 && i < 16){
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unsigned int digit = unum % base;
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if(digit < 10)
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buffer[i++] = '0' + digit;
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else
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buffer[i++] = 'A' + (digit - 10);
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unum = unum / base;
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}
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} else {
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// Decimal mode: handle negative with minus sign
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if(num < 0){
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lcd_data('-');
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num = -num;
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}
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if(num == 0){
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lcd_data('0');
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return;
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}
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while(num > 0 && i < 16){
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buffer[i++] = '0' + (num % 10);
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num = num / 10;
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}
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}
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while(i > 0){
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lcd_data(buffer[--i]);
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}
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}
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void display_mode(void){
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lcd_cmd(0x80);
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lcd_print_str("Mode: ");
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if(current_base == MODE_BIN)
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lcd_print_str("BIN ");
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else if(current_base == MODE_OCT)
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lcd_print_str("OCT ");
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else if(current_base == MODE_DEC)
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lcd_print_str("DEC ");
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else
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lcd_print_str("HEX ");
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}
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void display_input(void){
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lcd_cmd(0xC0);
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lcd_print_str("Inp: ");
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lcd_print_num(input_num, current_base);
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lcd_print_str(" ");
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}
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void display_operator_feedback(const char* op_symbol){
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// Brief feedback on line 2
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lcd_cmd(0xC0);
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lcd_print_str("Op: ");
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lcd_print_str(op_symbol);
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lcd_print_str(" ");
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delay(100000); // Brief delay to show feedback
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display_input(); // Return to showing input
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}
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unsigned int scan_keypad(void){
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unsigned int col, row;
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unsigned int row_bits;
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for(col=0; col<4; col++){
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LPC_GPIO0->FIOSET = COL_MASK;
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delay(50);
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LPC_GPIO0->FIOCLR = (1 << (COL_BASE + col));
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delay(200);
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row_bits = (LPC_GPIO0->FIOPIN & ROW_MASK) >> ROW_BASE;
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if(row_bits != 0x0F){
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for(row=0; row<4; row++){
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if((row_bits & (1<<row)) == 0){
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LPC_GPIO0->FIOSET = COL_MASK;
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return col*4 + row;
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}
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}
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}
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}
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LPC_GPIO0->FIOSET = COL_MASK;
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return 0xFF;
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}
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// Check if Key 0 is currently pressed (shift key)
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unsigned int is_key0_pressed(void){
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unsigned int col = 0; // Key 0 is at column 0, row 0
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unsigned int row_bits;
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LPC_GPIO0->FIOSET = COL_MASK;
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delay(50);
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LPC_GPIO0->FIOCLR = (1 << (COL_BASE + col));
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delay(200);
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row_bits = (LPC_GPIO0->FIOPIN & ROW_MASK) >> ROW_BASE;
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LPC_GPIO0->FIOSET = COL_MASK;
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// Check if row 0 is pressed (Key 0)
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return ((row_bits & 0x01) == 0) ? 1 : 0;
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}
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unsigned int scan_mode_button(void){
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// Return 1 if button is pressed (active low), 0 if not pressed
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return ((LPC_GPIO2->FIOPIN & MODE_BUTTON) == 0) ? 1 : 0;
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}
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unsigned int is_valid_digit(unsigned int key){
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if(key >= 16) return 0;
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if(current_base == MODE_BIN && key >= 2) return 0;
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if(current_base == MODE_OCT && key >= 8) return 0;
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if(current_base == MODE_DEC && key >= 10) return 0;
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// In HEX mode, all keys 0-15 are valid digits!
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return 1;
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}
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void change_mode(void){
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if(current_base == MODE_DEC)
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current_base = MODE_BIN;
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else if(current_base == MODE_BIN)
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current_base = MODE_OCT;
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else if(current_base == MODE_OCT)
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current_base = MODE_HEX;
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else
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current_base = MODE_DEC;
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display_mode();
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}
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int main(void){
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unsigned int key, last_key = 0xFF;
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unsigned int stable = 0;
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unsigned int button_state, last_button_state = 0;
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unsigned int button_stable = 0;
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unsigned int shift_active = 0;
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// Configure pins
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LPC_PINCON->PINSEL0 = 0;
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LPC_PINCON->PINSEL1 = 0;
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LPC_PINCON->PINSEL3 = 0;
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LPC_PINCON->PINSEL4 = 0; // Configure P2.12
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// Keypad: Columns output, Rows input
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LPC_GPIO0->FIODIR |= COL_MASK;
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LPC_GPIO0->FIODIR &= ~ROW_MASK;
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LPC_GPIO0->FIOSET = COL_MASK;
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// Mode button: Input with internal pull-up
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LPC_GPIO2->FIODIR &= ~MODE_BUTTON; // Set as input
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// 7-Segment
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LPC_GPIO0->FIODIR |= (0xFF << SEG_SHIFT);
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LPC_GPIO1->FIODIR |= DIGIT_EN;
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// LCD
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LPC_GPIO0->FIODIR |= LCD_DATA_MASK | LCD_RS | LCD_EN;
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lcd_init();
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display_mode();
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display_input();
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for(;;){
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// Check if shift key (Key 0) is being held
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shift_active = is_key0_pressed();
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// Scan for other keys
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key = scan_keypad();
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button_state = scan_mode_button();
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// Debounce keypad
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if(key == last_key){
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if(stable < 5) stable++;
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} else {
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last_key = key;
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stable = 0;
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}
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// Debounce mode button
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if(button_state == last_button_state){
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if(button_stable < 5) button_stable++;
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} else {
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last_button_state = button_state;
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button_stable = 0;
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}
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// Handle mode button press
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if(button_stable == 3 && button_state == 1){
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change_mode();
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button_stable = 5; // Prevent multiple triggers
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}
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// Handle keypad input
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if(stable == 3 && key != 0xFF){
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// Key pressed and stable
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// If Key 0 is also pressed, we're in operator mode
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if(shift_active && key != 0){
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// OPERATOR MODE (Key 0 + another key)
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if(key == 11){ // Key 0 + B = Addition
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stored_num = input_num;
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operation = OP_ADD;
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input_num = 0;
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display_operator_feedback("+");
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}
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else if(key == 12){ // Key 0 + C = Clear
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input_num = 0;
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stored_num = 0;
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operation = OP_NONE;
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result = 0;
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display_operator_feedback("CLR");
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}
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else if(key == 13){ // Key 0 + D = Subtraction
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stored_num = input_num;
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operation = OP_SUB;
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input_num = 0;
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display_operator_feedback("-");
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}
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else if(key == 14){ // Key 0 + E = Multiplication
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stored_num = input_num;
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operation = OP_MUL;
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input_num = 0;
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display_operator_feedback("*");
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}
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else if(key == 15){ // Key 0 + F = Equals
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if(operation == OP_ADD)
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result = stored_num + input_num;
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else if(operation == OP_SUB)
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result = stored_num - input_num;
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else if(operation == OP_MUL)
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result = stored_num * input_num;
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else
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result = input_num;
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lcd_cmd(0xC0);
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lcd_print_str("Res: ");
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lcd_print_num(result, current_base);
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lcd_print_str(" ");
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input_num = result;
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operation = OP_NONE;
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}
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}
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else {
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// NORMAL MODE - Digit input
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if(is_valid_digit(key)){
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input_num = input_num * current_base + key;
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// Handle overflow with wrap-around for signed int
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if(input_num > 32767) input_num = input_num % 32768;
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if(input_num < -32768) input_num = -32768;
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display_input();
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}
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}
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stable = 5; // Prevent repeated triggers
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}
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// Display result on 7-segment (last digit only)
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// MODIFIED: Use decimal point to indicate negative numbers
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int display_value = (input_num < 0) ? -input_num : input_num;
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unsigned int display_digit = display_value % 16;
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unsigned int seg_pattern = seven_seg[display_digit];
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// Turn on decimal point if number is negative
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if(input_num < 0){
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seg_pattern |= 0x80; // Bit 7 is the decimal point
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}
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LPC_GPIO0->FIOCLR = (0xFF << SEG_SHIFT);
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LPC_GPIO0->FIOSET = (seg_pattern << SEG_SHIFT);
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LPC_GPIO1->FIOSET = DIGIT_EN;
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delay(3000);
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}
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}
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