From 9545c01150b93fe646976ffcd06d5bcbc50f7cc3 Mon Sep 17 00:00:00 2001
From: Gregory Ballantine <gballantine@metaunix.net>
Date: Mon, 7 Sep 2026 22:10:46 -0400
Subject: [PATCH] [Issue #4] - Added blinking colon to signify that the clock
 is not frozen; also moved to a more "event-driven" approach to refreshing the
 display to cut down on wasted display cycles

---
 main.py | 48 ++++++++++++++++++++++++++++--------------------
 1 file changed, 28 insertions(+), 20 deletions(-)

diff --git a/main.py b/main.py
index e1aadd8..dfadba4 100644
--- a/main.py
+++ b/main.py
@@ -88,30 +88,38 @@ def calculate_x_spacing(text, scale=1):
 DAYS = ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"]
 TIME_Y = 12  # Keep vertical placement consistent
 
+last_second = -1
+
 while True:
+    # 1. Compute time
     local_epoch = time.time() + (Config.UTC_OFFSET * 3600)
-    year, month, day, hour_24, minute, _, weekday, _ = time.localtime(local_epoch)
+    year, month, day, hour_24, minute, second, weekday, _ = time.localtime(local_epoch)
 
-    # 1. Format time string and period
-    if Config.USE_24_HOUR:
-        time_str = f"{hour_24:02d}:{minute:02d}"
-        period = None
-    else:
-        hour_12 = hour_24 % 12 or 12  # Replaces the 4-line if hour_12 == 0 block
-        time_str = f"{hour_12}:{minute:02d}"
-        period = "AM" if hour_24 < 12 else "PM"
+    # 2. Only redraw if the second has actually changed
+    if second != last_second:
+        last_second = second
 
-    # 2. Render time and AM/PM
-    oled.fill(0)
-    time_x = calculate_x_spacing(time_str, scale=2)
-    draw_scaled_text(oled, time_str, x=time_x, y=TIME_Y, scale=2)
+        sep = ":" if second % 2 == 0 else " "
 
-    if period:
-        oled.text(period, time_x + (len(time_str) * 16) + 4, TIME_Y + 8)
+        if Config.USE_24_HOUR:
+            time_str = f"{hour_24:02d}{sep}{minute:02d}"
+            period = None
+        else:
+            hour_12 = hour_24 % 12 or 12
+            time_str = f"{hour_12}{sep}{minute:02d}"
+            period = "AM" if hour_24 < 12 else "PM"
 
-    # 3. Render date centered underneath
-    date_str = f"{DAYS[weekday]} {year}-{month:02d}-{day:02d}"
-    oled.text(date_str, calculate_x_spacing(date_str), 42)
+        oled.fill(0)
+        time_x = calculate_x_spacing(time_str, scale=2)
+        draw_scaled_text(oled, time_str, x=time_x, y=TIME_Y, scale=2)
 
-    oled.show()
-    time.sleep(0.5)
+        if period:
+            oled.text(period, time_x + (len(time_str) * 16) + 4, TIME_Y + 8)
+
+        date_str = f"{DAYS[weekday]} {year}-{month:02d}-{day:02d}"
+        oled.text(date_str, calculate_x_spacing(date_str), 42)
+
+        oled.show()
+
+    # 3. Sleep in small increments to catch the exact second boundary with minimal latency
+    time.sleep_ms(20)