Merge pull request #23 from martinwoodward/worldclock-clear-screen-on…

…-start

Woldclock: Clear screen before network call delay

examples/word_clock.py

@@ -9,6 +9,14 @@
 presto = Presto()
 display = presto.display
 WIDTH, HEIGHT = display.get_bounds()
+BLACK = display.create_pen(0, 0, 0)
+WHITE = display.create_pen(200, 200, 200)
+GRAY = display.create_pen(30, 30, 30)
+
+# Clear the screen before the network call is made
+display.set_pen(BLACK)
+display.clear()
+presto.update()
 
 # Length of time between updates in minutes.
 UPDATE_INTERVAL = 15
@@ -24,11 +32,6 @@
 # Set the correct time using the NTP service.
 ntptime.settime()
 
-BLACK = display.create_pen(0, 0, 0)
-WHITE = display.create_pen(200, 200, 200)
-GRAY = display.create_pen(30, 30, 30)
-
-
 def approx_time(hours, minutes):
     nums = {0: "twelve", 1: "one", 2: "two",
             3: "three", 4: "four", 5: "five", 6: "six",