From fd3ec40397b6934cbfc5417c00b5c1c9400ddf0d Mon Sep 17 00:00:00 2001
From: sherlock <aadit@aaditagrawal.com>
Date: Thu, 16 Oct 2025 12:59:30 +0530
Subject: [PATCH] Updated data for ES

---
 ES/Project/code.c | 63 ++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 49 insertions(+), 14 deletions(-)

diff --git a/ES/Project/code.c b/ES/Project/code.c
index 9a4a9dc..bba0fcf 100644
--- a/ES/Project/code.c
+++ b/ES/Project/code.c
@@ -19,15 +19,19 @@
  *   RS:   P0.27
  *   EN:   P0.28
  *
+ * MODE BUTTON:
+ *   P2.12 (Input, internal pull-up)
+ *
  * KEY FUNCTIONS:
  *   0-9: Digit input (valid in all bases based on base)
  *   A-F: Digit input (valid only in appropriate base)
- *   Key A (10): Mode/Base selection (cycles: BIN->OCT->DEC->HEX)
+ *   Key A (10): Digit input (value 10 in HEX mode)
  *   Key B (11): Addition (+)
  *   Key C (12): Clear (C)
  *   Key D (13): Subtraction (-)
  *   Key E (14): Multiplication (*)
  *   Key F (15): Equals (=)
+ *   P2.12 Button: Mode selection (cycles: DEC->BIN->OCT->HEX)
  */
 
 // 7-Segment patterns
@@ -52,6 +56,9 @@ const unsigned char seven_seg[16] = {
 #define LCD_RS (1<<27)
 #define LCD_EN (1<<28)
 
+// Mode button defines
+#define MODE_BUTTON (1<<12)
+
 // Calculator states
 #define MODE_BIN 2
 #define MODE_OCT 8
@@ -197,6 +204,11 @@ unsigned int scan_keypad(void){
     return 0xFF;
 }
 
+unsigned int scan_mode_button(void){
+    // Return 1 if button is pressed (active low), 0 if not pressed
+    return ((LPC_GPIO2->FIOPIN & MODE_BUTTON) == 0) ? 1 : 0;
+}
+
 unsigned int is_valid_digit(unsigned int key){
     if(key >= 16) return 0;
     if(current_base == MODE_BIN && key >= 2) return 0;
@@ -205,20 +217,39 @@ unsigned int is_valid_digit(unsigned int key){
     return 1;
 }
 
+void change_mode(void){
+    if(current_base == MODE_DEC)
+        current_base = MODE_BIN;
+    else if(current_base == MODE_BIN)
+        current_base = MODE_OCT;
+    else if(current_base == MODE_OCT)
+        current_base = MODE_HEX;
+    else
+        current_base = MODE_DEC;
+    display_mode();
+}
+
 int main(void){
     unsigned int key, last_key = 0xFF;
     unsigned int stable = 0;
+    unsigned int button_state, last_button_state = 0;
+    unsigned int button_stable = 0;
 
     // Configure pins
     LPC_PINCON->PINSEL0 = 0;
     LPC_PINCON->PINSEL1 = 0;
     LPC_PINCON->PINSEL3 = 0;
+    LPC_PINCON->PINSEL4 = 0;  // Configure P2.12
 
     // Keypad: Columns output, Rows input
     LPC_GPIO0->FIODIR |= COL_MASK;
     LPC_GPIO0->FIODIR &= ~ROW_MASK;
     LPC_GPIO0->FIOSET = COL_MASK;
 
+    // Mode button: Input with internal pull-up
+    LPC_GPIO2->FIODIR &= ~MODE_BUTTON;  // Set as input
+    // Note: Internal pull-up is enabled by default on LPC17xx
+
     // 7-Segment
     LPC_GPIO0->FIODIR |= (0xFF << SEG_SHIFT);
     LPC_GPIO1->FIODIR |= DIGIT_EN;
@@ -232,8 +263,9 @@ int main(void){
 
     for(;;){
         key = scan_keypad();
+        button_state = scan_mode_button();
 
-        // Debounce
+        // Debounce keypad
         if(key == last_key){
             if(stable < 5) stable++;
         } else {
@@ -241,6 +273,21 @@ int main(void){
             stable = 0;
         }
 
+        // Debounce mode button
+        if(button_state == last_button_state){
+            if(button_stable < 5) button_stable++;
+        } else {
+            last_button_state = button_state;
+            button_stable = 0;
+        }
+
+        // Handle mode button press
+        if(button_stable == 3 && button_state == 1){
+            change_mode();
+            button_stable = 5;  // Prevent multiple triggers
+        }
+
+        // Handle keypad input
         if(stable == 3 && key != 0xFF){
             // Key pressed and stable
 
@@ -250,18 +297,6 @@ int main(void){
                 if(input_num > 9999) input_num = input_num % 10000;
                 display_input();
             }
-            // Mode selection (Key A / 10)
-            else if(key == 10){
-                if(current_base == MODE_BIN)
-                    current_base = MODE_OCT;
-                else if(current_base == MODE_OCT)
-                    current_base = MODE_DEC;
-                else if(current_base == MODE_DEC)
-                    current_base = MODE_HEX;
-                else
-                    current_base = MODE_BIN;
-                display_mode();
-            }
             // Addition (Key B / 11)
             else if(key == 11){
                 stored_num = input_num;