From dd2c41c0b9dbc89de31e2e955e6d88cea93b0c21 Mon Sep 17 00:00:00 2001
From: sherlock <aadit@aaditagrawal.com>
Date: Thu, 16 Oct 2025 11:07:04 +0530
Subject: [PATCH] Updated data for ES

---
 ES/Lab/Lab9/keyp.c | 160 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 160 insertions(+)
 create mode 100644 ES/Lab/Lab9/keyp.c

diff --git a/ES/Lab/Lab9/keyp.c b/ES/Lab/Lab9/keyp.c
new file mode 100644
index 0000000..7e902dd
--- /dev/null
+++ b/ES/Lab/Lab9/keyp.c
@@ -0,0 +1,160 @@
+#include <LPC17xx.h>
+
+#define RS_CTRL 0x08000000
+#define EN_CTRL 0x10000000
+#define DT_CTRL 0x07800000
+
+#define COL_BASE_BIT    15
+#define ROW_BASE_BIT    19
+#define COL_MASK ((0x0F) << COL_BASE_BIT)
+#define ROW_MASK ((0x0F) << ROW_BASE_BIT)
+
+unsigned long int temp1 = 0, temp2 = 0, i;
+unsigned char flag1 = 0, flag2 = 0;
+
+unsigned long int init_command[] = {
+    0x30, 0x30, 0x30, 0x20, 0x28, 0x0C, 0x01, 0x80
+};
+
+const unsigned char key_chars[16] = {
+    '0','1','2','3','4','5','6','7',
+    '8','9','A','B','C','D','E','F'
+};
+
+void lcd_write(void);
+void port_write(void);
+void delay_lcd(unsigned long);
+void short_delay(volatile unsigned int d);
+void lcd_display_key(unsigned char key);
+
+int main(void) {
+    unsigned int col_idx, row_idx;
+    unsigned int candidate = 0xFF;
+    unsigned int stable = 0;
+    unsigned int displayed = 0xFF;
+    unsigned int row_bits;
+
+    LPC_PINCON->PINSEL0 &= ~(0xFFFFFFFF);
+    LPC_PINCON->PINSEL1 &= ~(0xFFFFFFFF);
+
+    LPC_GPIO0->FIODIR = DT_CTRL | RS_CTRL | EN_CTRL;
+    LPC_GPIO0->FIODIR |= COL_MASK;
+    LPC_GPIO0->FIODIR &= ~ROW_MASK;
+
+    LPC_GPIO0->FIOSET = COL_MASK;
+
+    flag1 = 0;
+    for (i = 0; i < 8; i++) {
+        temp1 = init_command[i];
+        lcd_write();
+    }
+
+    flag1 = 0;
+    temp1 = 0x80;
+    lcd_write();
+
+    flag1 = 1;
+    temp1 = 'K';
+    lcd_write();
+    temp1 = 'e';
+    lcd_write();
+    temp1 = 'y';
+    lcd_write();
+    temp1 = ':';
+    lcd_write();
+    temp1 = ' ';
+    lcd_write();
+
+    for(;;) {
+        unsigned int read_key = 0xFF;
+
+        for(col_idx = 0; col_idx < 4; col_idx++) {
+            LPC_GPIO0->FIOSET = COL_MASK;
+            short_delay(50);
+            LPC_GPIO0->FIOCLR = (1 << (COL_BASE_BIT + col_idx));
+            short_delay(200);
+
+            row_bits = (LPC_GPIO0->FIOPIN & ROW_MASK) >> ROW_BASE_BIT;
+
+            if(row_bits != 0x0F) {
+                for(row_idx = 0; row_idx < 4; row_idx++) {
+                    if((row_bits & (1 << row_idx)) == 0) {
+                        read_key = col_idx * 4 + row_idx;
+                        break;
+                    }
+                }
+                LPC_GPIO0->FIOSET = COL_MASK;
+                break;
+            }
+            LPC_GPIO0->FIOSET = COL_MASK;
+        }
+
+        if(read_key == candidate) {
+            if(stable < 3) stable++;
+        } else {
+            candidate = read_key;
+            stable = 1;
+        }
+
+        if(stable >= 3) {
+            if(candidate != 0xFF && candidate != displayed) {
+                displayed = candidate;
+                lcd_display_key(displayed);
+            }
+            stable = 3;
+        }
+
+        short_delay(3000);
+    }
+}
+
+void lcd_display_key(unsigned char key) {
+    flag1 = 0;
+    temp1 = 0x85;
+    lcd_write();
+
+    flag1 = 1;
+    temp1 = key_chars[key];
+    lcd_write();
+}
+
+void short_delay(volatile unsigned int d) {
+    while(d--) __NOP();
+}
+
+void lcd_write(void) {
+    flag2 = (flag1 == 1) ? 0 :
+            (((temp1 == 0x30) || (temp1 == 0x20)) ? 1 : 0);
+
+    temp2 = temp1 & 0xf0;
+    temp2 = temp2 << 19;
+    port_write();
+
+    if (!flag2) {
+        temp2 = temp1 & 0x0f;
+        temp2 = temp2 << 23;
+        port_write();
+    }
+}
+
+void port_write(void) {
+    LPC_GPIO0->FIOPIN = temp2;
+
+    if (flag1 == 0) {
+        LPC_GPIO0->FIOCLR = RS_CTRL;
+    } else {
+        LPC_GPIO0->FIOSET = RS_CTRL;
+    }
+
+    LPC_GPIO0->FIOSET = EN_CTRL;
+    delay_lcd(100);
+    LPC_GPIO0->FIOCLR = EN_CTRL;
+
+    delay_lcd(500000);
+}
+
+void delay_lcd(unsigned long r1) {
+    unsigned long r;
+    for (r = 0; r < r1; r++);
+    return;
+}