From 9db9ac05ce674ed9ead06d92d423fb0995cc9a42 Mon Sep 17 00:00:00 2001
From: aadit <aadit@noreply.localhost>
Date: Thu, 25 Sep 2025 13:01:27 +0530
Subject: [PATCH] Add ES/Lab/Lab8/16KeyMatrixOn7Seg.c

---
 ES/Lab/Lab8/16KeyMatrixOn7Seg.c | 79 +++++++++++++++++++++++++++++++++
 1 file changed, 79 insertions(+)
 create mode 100644 ES/Lab/Lab8/16KeyMatrixOn7Seg.c

diff --git a/ES/Lab/Lab8/16KeyMatrixOn7Seg.c b/ES/Lab/Lab8/16KeyMatrixOn7Seg.c
new file mode 100644
index 0000000..dcb4e58
--- /dev/null
+++ b/ES/Lab/Lab8/16KeyMatrixOn7Seg.c
@@ -0,0 +1,79 @@
+#include <LPC17xx.h>
+
+const unsigned char seven_seg[16] = {
+    0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07,
+    0x7F,0x6F,0x77,0x7C,0x39,0x5E,0x79,0x71
+};
+
+#define SEG_SHIFT       4
+#define DIGIT_ENABLE_P1 (1<<23)
+#define DIGIT_ENABLE_MASK (0x0F<<23)
+#define COL_BASE_BIT    15
+#define ROW_BASE_BIT    19
+#define COL_MASK ((0x0F) << COL_BASE_BIT)
+#define ROW_MASK ((0x0F) << ROW_BASE_BIT)
+
+static void short_delay(volatile unsigned int d){ while(d--) __NOP(); }
+
+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 |= (0xFF << SEG_SHIFT);
+    LPC_GPIO0->FIODIR |= COL_MASK;
+    LPC_GPIO0->FIODIR &= ~ROW_MASK;
+    LPC_GPIO1->FIODIR |= DIGIT_ENABLE_MASK;
+    LPC_GPIO0->FIOPIN &= ~(0xFF << SEG_SHIFT);
+    LPC_GPIO1->FIOPIN &= ~DIGIT_ENABLE_MASK;
+    LPC_GPIO0->FIOSET = COL_MASK;
+
+    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){
+                displayed = candidate & 0x0F;
+            }
+            stable = 3;
+        }
+
+        if(displayed != 0xFF){
+            unsigned int seg = seven_seg[displayed];
+            LPC_GPIO0->FIOCLR = (0xFF << SEG_SHIFT);
+            LPC_GPIO0->FIOSET = (seg << SEG_SHIFT);
+            LPC_GPIO1->FIOCLR = DIGIT_ENABLE_MASK;
+            LPC_GPIO1->FIOSET = DIGIT_ENABLE_P1;
+        }
+
+        short_delay(3000);
+    }
+}