Adding comments

examples/lib/PrestoLight.py

@@ -1,45 +1,57 @@
 import plasma
 from struct import unpack
+from micropython import const
 
 
 class Section(object):
-    # A section is an 30 x 30 area of the screen
-    # Of this section we will then use 100 sample points to get the average colour
+    # A section of the screen we'll use for sampling.
+    # We're using 80 x 80 sections and sampling 49 points within that space
     def __init__(self, x, y):
         self.X = const(x)
         self.Y = const(y)
         self.WIDTH = const(80)
         self.HEIGHT = const(80)
         self.colours = []
-        self.x_range = range(self.X, self.X + self.WIDTH, 12)
-        self.y_range = range(self.Y, self.Y + self.HEIGHT, 12)
+
+        # Pre calculate the range to use later
+        self.x_range = range(self.X, self.X + self.WIDTH, 10)
+        self.y_range = range(self.Y, self.Y + self.HEIGHT, 10)
 
     @micropython.native
     def return_avg(self, display):
 
+        # Running total of the RGB values for our average calculation later
         r_value, g_value, b_value = 0, 0, 0
+
+        # Counter
         c = 0
 
         for x in self.x_range:
             for y in self.y_range:
 
+                # Grab the pixel colour value back from the framebuffer
                 offset = (y * 240 + x) * 2
                 mv = memoryview(display)
                 rgb = mv[offset:offset + 2]
                 rgb = unpack("<H", rgb)
 
-                # GGGBBBBBRRRRRGGG
+                # Now we need to sort and arrange those bits into their R G and B values
+                # We can't get back the exact value due to the destructive nature of converting to RGB565
+                # But it's close enough for displaying a colour on the backlight :)
+
                 r = (rgb[0] >> 3) & 0b00011111
                 g = (rgb[0] >> 13) & 0b00000111 | rgb[0] << 3 & 0b00111000
                 b = (rgb[0] >> 8) & 0b00011111
 
-                # Scale and add to total
+                # Scale the raw RGB values and add them to our running total
                 r_value += r << 3
                 g_value += g << 2
                 b_value += b << 3
 
+                # Add 1 to the counter
                 c += 1
 
+        # Now we finish the average calculation and return the value as an integer
         r_value = int(r_value / c)
         g_value = int(g_value / c)
         b_value = int(b_value / c)
@@ -50,10 +62,13 @@ def return_avg(self, display):
 class Reactive(object):
     def __init__(self):
 
+        # Some consts for the max, mid and min points
         MAX = const(160)
         MID = const(80)
         MIN = const(0)
 
+        # The index for each section matches the index for the Backlight LED
+        # Section 0 and LED 0 is in the bottom right corner as you're looking at the screen
         self.sections = [Section(MAX, MAX), Section(MAX, MID), Section(MAX, MIN), Section(MID, MIN),
                          Section(MIN, MIN), Section(MIN, MID), Section(MIN, MAX)]
 
@@ -62,6 +77,7 @@ def __init__(self):
         self.bl.start()
 
     def update(self, display):
+        # For each section we get the average colour in that area and set the backlight LED to that colour
         for i, section in enumerate(self.sections):
             colour = section.return_avg(display)
             self.bl.set_rgb(i, colour[0], colour[1], colour[2])