diff --git a/lab_3/lab_3.c b/lab_3/lab_3.c
index f96e5ff..a2cc777 100644
--- a/lab_3/lab_3.c
+++ b/lab_3/lab_3.c
@@ -1,4 +1,5 @@
 /**
+ * Lab 3
  * To develop a simple stopwatch that measures time intervals between
  * button presses.
  *
@@ -18,21 +19,35 @@
 #include "pico/stdlib.h"
 #include "hardware/gpio.h"
 
-#define PSEUDO_BTN 15
-#define DELAY_US 1000000
+#define PSEUDO_BTN  15          // GPIO 15 is the pseudo-button
+#define DELAY_US    1000000     // 1-second delay for repeating timer
+#define DEBOUNCE_MS 200         // Debounce delay
 
-unsigned long long time = 0;
-struct repeating_timer timer;
+unsigned long long time = 0;    // Elapsed time
+struct repeating_timer timer;   // Repeating timer
 
-bool repeating_timer_callback(struct repeating_timer *t) {
+/**
+ * Callback function for repeating timer
+ * This function will print the elapsed time every second as required by the
+ * lab specification.
+ * @param t    The timer that triggered the callback
+ * @return     True to keep the timer running, false to stop it
+ */
+bool repeating_timer_callback (struct repeating_timer *t) {
     // Print elapsed time every second
     printf("Elapsed Time: %llus\n",
            (time_us_64() - time) / 1000000);
     return true;
 }
 
-
-void gpio_callback(uint gpio, uint32_t events) {
+/**
+ * Interrupt callback function for pseudo-button (pull-up)
+ * This function will start the timer on button press (falling edge)
+ * and stop the timer on button release. (rising edge)
+ * @param gpio      The GPIO pin that triggered the interrupt
+ * @param events    The type of interrupt that triggered the callback
+ */
+void gpio_callback (uint gpio, uint32_t events) {
     // Start timer on button press
     if (gpio == PSEUDO_BTN && events == GPIO_IRQ_EDGE_FALL)
     {
@@ -44,24 +59,32 @@ void gpio_callback(uint gpio, uint32_t events) {
                 repeating_timer_callback,
                 NULL,
                 &timer
-                );
+        );
     }
     // Stop timer on button release
-    else if (gpio == PSEUDO_BTN && events == GPIO_IRQ_EDGE_RISE)
+    else
     {
-        printf("Timer Stopped at %llu\n", time_us_64());
-        cancel_repeating_timer(&timer);
+        if (gpio == PSEUDO_BTN && events == GPIO_IRQ_EDGE_RISE)
+        {
+            printf("Timer Stopped at %llu\n", time_us_64());
+            cancel_repeating_timer(&timer);
 
-        // Print elapsed time and reset
-        printf("Final Elapsed Time: %llus\n",
-               (time_us_64() - time) / 1000000);
+            // Print elapsed time and reset
+            printf("Final Elapsed Time: %llus\n",
+                   (time_us_64() - time) / 1000000);
 
-        time = 0;
+            time = 0;
+        }
     }
 }
 
-static void btn_init()
-{
+/**
+ * Initialize the pseudo-button (pull-up)
+ * The pseudo-button is connected to GPIO 15 and is configured as an input
+ * with a pull-up resistor.
+ * The interrupt is configured to trigger on both rising and falling edges.
+ */
+static void btn_init () {
     gpio_init(PSEUDO_BTN);
     gpio_set_dir(PSEUDO_BTN, GPIO_IN);
     gpio_set_pulls(PSEUDO_BTN, true, false);
@@ -74,13 +97,15 @@ static void btn_init()
     );
 }
 
-int main()
-{
+int main () {
     stdio_init_all();
     btn_init();
 
-    while (true) {
+    while (true)
+    {
         tight_loop_contents();
+        // Debounce
+        sleep_ms(DEBOUNCE_MS);
     }
 
 }