capitalize variable constants

Change-Id: I2e8a61b1ea58fe3a85ee227a6212e0f4ec0dedd6
diff --git a/raspimon_eats.py b/raspimon_eats.py
index e1c7764..18fd8d5 100644
--- a/raspimon_eats.py
+++ b/raspimon_eats.py
@@ -7,11 +7,11 @@
 # Variables ---------------------------
 raspimon = [2,4]
 berries = []
-white = (255, 255, 255)
-blank = (0, 0, 0)
-red = (255, 0, 0)
 direction = "right"
-pause = 1.0
+WHITE = (255, 255, 255)
+RED = (255, 0, 0)
+BLANK = (0, 0, 0)
+DELAY = 1.0
 
 # Functions ---------------------------
 def move():
@@ -47,8 +47,8 @@
       next[1] = raspimon[1] - 1
 
   # Update the position
-  sense.set_pixel(raspimon[0], raspimon[1], blank)
-  sense.set_pixel(next[0], next[1], white)
+  sense.set_pixel(raspimon[0], raspimon[1], BLANK)
+  sense.set_pixel(next[0], next[1], WHITE)
 
   # If next position is a berry, eat it
   if next in berries:
@@ -64,7 +64,7 @@
   x = randint(0, 7)
   y = randint(0, 7)
   new = [x, y]
-  sense.set_pixel(x, y, red)
+  sense.set_pixel(x, y, RED)
   berries.append(new)
 
 # Main program ------------------------
@@ -76,7 +76,7 @@
 
 while True:
   move()
-  sleep(pause)
+  sleep(DELAY)
   if len(berries) == 0:
     break