From fe6ce3a9bbcbf9057dc5c794afcbae2a1d10e640 Mon Sep 17 00:00:00 2001
From: dherrada <dylan.herrada@gmail.com>
Date: Fri, 12 Jun 2020 16:28:53 -0400
Subject: [PATCH] better names, more documentation

---
 Circuit_Playground_Brake_Light/code.py | 39 +++++++++++++++-----------
 1 file changed, 23 insertions(+), 16 deletions(-)

diff --git a/Circuit_Playground_Brake_Light/code.py b/Circuit_Playground_Brake_Light/code.py
index 288133e62..841604eef 100644
--- a/Circuit_Playground_Brake_Light/code.py
+++ b/Circuit_Playground_Brake_Light/code.py
@@ -3,14 +3,20 @@ import math
 from adafruit_circuitplayground import cp
 
 brightness = 0
-l10 = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
-l50 = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-       0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-       0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-       0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-       0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
 
-i = 0
+# List that holds the last 10 z-axis acceleration values read from the accelerometer.
+# Used for the n=10 moving average
+last10 = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
+
+# List that holds the last 50 z-axis acceleration values read from the accelerometer.
+# Used for the n=50 moving average
+last50 = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+          0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+          0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+          0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+          0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
+
+consecutive_triggers = 0
 cp.pixels.fill((255, 0, 0))
 
 light_on = False
@@ -19,27 +25,28 @@ while True:
     x, y, z = cp.acceleration
 
     # moving average n=10, not super smooth, but it substantially lowers the amount of noise
-    l10.append(z)
-    l10.pop(0)
-    avg10 = sum(l10)/10
+    last10.append(z)
+    last10.pop(0)
+    avg10 = sum(last10)/10
 
     # moving average n=50, very smooth
-    l50.append(z)
-    l50.pop(0)
-    avg50 = sum(l50)/50
+    last50.append(z)
+    last50.pop(0)
+    avg50 = sum(last50)/50
 
     # If the difference between the moving average of the last 10 points and the moving average of
     # the last 50 points is greater than 1 m/s^2, this is true
     if avg10 - avg50 > 1:
-        if i > 3:
+        if consecutive_triggers > 3: # Is true when avg10-avg50 > 1m/s^2 at least 3 times in a row
             # Detects shake. Due to the very low shake threshold, this alone would have very low
             # specificity. This was mitigated by having it only run when the acceleration
             # difference is greater than 1 m/s^2 at least 3 times in a row.
             if not cp.shake(shake_threshold=10):
+                # Set brightness to max, timestamp when it was set to max, and set light_on to true
                 cp.pixels.brightness = 1
                 start = time.monotonic()
                 light_on = True
-        i += 1
+        consecutive_triggers += 1 # increase it whether or not the light is turned on
 
     # light_on variable is for short circuiting. Not really necessary, just makes things run faster
     elif not light_on or time.monotonic() - start > 0.4:
@@ -47,7 +54,7 @@ while True:
         # Max brightness can be adjusted with the coefficient.
         cp.pixels.brightness = abs(math.sin(brightness)) * 0.5
         brightness += 0.05
-        i = 0
+        consecutive_triggers = 0
         light_on = False
 
     time.sleep(0.02)