From f76019f31cb8c4386bc0c3e96a38a5f7c73ecb53 Mon Sep 17 00:00:00 2001
From: Mike Bell <mike@mercuna.com>
Date: Sat, 29 Oct 2022 13:02:42 +0100
Subject: [PATCH] Add time synchronization from NTP to GU clock example

---
 .../examples/galactic_unicorn/clock.py        | 107 ++++++++++++++++--
 1 file changed, 100 insertions(+), 7 deletions(-)

diff --git a/micropython/examples/galactic_unicorn/clock.py b/micropython/examples/galactic_unicorn/clock.py
index e56278d9..13fce333 100644
--- a/micropython/examples/galactic_unicorn/clock.py
+++ b/micropython/examples/galactic_unicorn/clock.py
@@ -1,9 +1,30 @@
+# Clock example with NTP synchronization
+#
+# Create a secrets.py with your Wifi details to be able to get the time
+# when the Galactic Unicorn isn't connected to Thonny.
+#
+# secrets.py should contain:
+# WIFI_SSID = "Your WiFi SSID"
+# WIFI_PASSWORD = "Your WiFi password"
+#
+# Clock synchronizes time on start, and resynchronizes if you press the A button
+
 import time
 import math
 import machine
+import network
+import ntptime
 from galactic import GalacticUnicorn
 from picographics import PicoGraphics, DISPLAY_GALACTIC_UNICORN as DISPLAY
 
+try:
+    from secrets import WIFI_SSID, WIFI_PASSWORD
+    wifi_available = True
+except ImportError:
+    print("Create secrets.py with your WiFi credentials to get time from NTP")
+    wifi_available = False
+
+
 # constants for controlling the background colour throughout the day
 MIDDAY_HUE = 1.1
 MIDNIGHT_HUE = 0.8
@@ -90,21 +111,76 @@ def outline_text(text, x, y):
     graphics.text(text, x, y, -1, 1)
 
 
+# Connect to wifi and synchronize the RTC time from NTP
+def sync_time():
+    if not wifi_available:
+        return
+
+    # Start connection
+    wlan = network.WLAN(network.STA_IF)
+    wlan.active(True)
+    wlan.connect(WIFI_SSID, WIFI_PASSWORD)
+
+    # Wait for connect success or failure
+    max_wait = 100
+    while max_wait > 0:
+        if wlan.status() < 0 or wlan.status() >= 3:
+            break
+        max_wait -= 1
+        print('waiting for connection...')
+        time.sleep(0.2)
+
+        redraw_display_if_reqd()
+        gu.update(graphics)
+
+    if max_wait > 0:
+        print("Connected")
+
+        try:
+            ntptime.settime()
+            print("Time set")
+        except OSError:
+            pass
+
+    wlan.disconnect()
+    wlan.active(False)
+
+
+# NTP synchronizes the time to UTC, this allows you to adjust the displayed time
+# by one hour increments from UTC by pressing the volume up/down buttons
+#
+# We use the IRQ method to detect the button presses to avoid incrementing/decrementing
+# multiple times when the button is held.
+utc_offset = 0
+
+up_button = machine.Pin(GalacticUnicorn.SWITCH_VOLUME_UP, machine.Pin.IN, machine.Pin.PULL_UP)
+down_button = machine.Pin(GalacticUnicorn.SWITCH_VOLUME_DOWN, machine.Pin.IN, machine.Pin.PULL_UP)
+
+
+def adjust_utc_offset(pin):
+    global utc_offset
+    if pin == up_button:
+        utc_offset += 1
+    if pin == down_button:
+        utc_offset -= 1
+
+
+up_button.irq(trigger=machine.Pin.IRQ_FALLING, handler=adjust_utc_offset)
+down_button.irq(trigger=machine.Pin.IRQ_FALLING, handler=adjust_utc_offset)
+
+
 year, month, day, wd, hour, minute, second, _ = rtc.datetime()
 
 last_second = second
 
-gu.set_brightness(0.5)
 
-while True:
-    if gu.is_pressed(GalacticUnicorn.SWITCH_BRIGHTNESS_UP):
-        gu.adjust_brightness(+0.01)
-
-    if gu.is_pressed(GalacticUnicorn.SWITCH_BRIGHTNESS_DOWN):
-        gu.adjust_brightness(-0.01)
+# Check whether the RTC time has changed and if so redraw the display
+def redraw_display_if_reqd():
+    global year, month, day, wd, hour, minute, second, last_second
 
     year, month, day, wd, hour, minute, second, _ = rtc.datetime()
     if second != last_second:
+        hour += utc_offset
         time_through_day = (((hour * 60) + minute) * 60) + second
         percent_through_day = time_through_day / 86400
         percent_to_midday = 1.0 - ((math.cos(percent_through_day * math.pi * 2) + 1) / 2)
@@ -131,6 +207,23 @@ while True:
 
         last_second = second
 
+
+gu.set_brightness(0.5)
+
+sync_time()
+
+while True:
+    if gu.is_pressed(GalacticUnicorn.SWITCH_BRIGHTNESS_UP):
+        gu.adjust_brightness(+0.01)
+
+    if gu.is_pressed(GalacticUnicorn.SWITCH_BRIGHTNESS_DOWN):
+        gu.adjust_brightness(-0.01)
+
+    if gu.is_pressed(GalacticUnicorn.SWITCH_A):
+        sync_time()
+
+    redraw_display_if_reqd()
+
     # update the display
     gu.update(graphics)