diff --git a/latex/pilight.zip b/latex/pilight.zip
index e001f72..ff6bc68 100644
Binary files a/latex/pilight.zip and b/latex/pilight.zip differ
diff --git a/pilight.pdf b/pilight.pdf
new file mode 100644
index 0000000..bffdf5a
Binary files /dev/null and b/pilight.pdf differ
diff --git a/py/led.py b/py/led.py
index 16fc1e8..09e617f 100644
--- a/py/led.py
+++ b/py/led.py
@@ -1,11 +1,12 @@
 import RPi.GPIO as GPIO
 import time
 
-LED_PIN = 17
+LED_PIN = 17    # GPIO phisical pin
 
 GPIO.setmode(GPIO.BCM)
 GPIO.setup(LED_PIN, GPIO.OUT)
 
+# Alternate every second, turning an LED on and off. Stopped by CTRL+C
 try:
     while True:
         GPIO.output(LED_PIN, GPIO.HIGH)
diff --git a/py/speech.py b/py/speech.py
index 2f85b05..2d8fbf9 100644
--- a/py/speech.py
+++ b/py/speech.py
@@ -2,9 +2,11 @@ import speech_recognition as sr
 
 recognizer = sr.Recognizer()
 with sr.Microphone() as source:
+    # audio input
     print("Say something...")
     audio = recognizer.listen(source)
     try:
+        # runs the live recored audio through PocketSphinx and print it as text
         text = recognizer.recognize_sphinx(audio)
         print("Sphinx recognized: {}".format(text))
     except sr.UnknownValueError:
diff --git a/py/speech_coltrol_led.py b/py/speech_coltrol_led.py
index ef67042..d369bcf 100644
--- a/py/speech_coltrol_led.py
+++ b/py/speech_coltrol_led.py
@@ -2,25 +2,30 @@ import speech_recognition as sr
 import RPi.GPIO as GPIO
 import time
 
-LED_PIN = 17
+LED_PIN = 17    # Number of GPIO physical pin
 
 # GPIO setup
 GPIO.setmode(GPIO.BCM)
 GPIO.setup(LED_PIN, GPIO.OUT)
 
+# turn LED on or off with correct command
 def trigger_action(command):
+    # turn LED on with command fire
     if "fire" in command.lower():
         GPIO.output(LED_PIN, GPIO.HIGH)
         print("Light ON")
+    # turn LED off with command night
     elif "night" in command.lower():
         GPIO.output(LED_PIN, GPIO.LOW)
         print("Light OFF")
 
 recognizer = sr.Recognizer()
 with sr.Microphone() as source:
+    # audio input
     print("Say a command...")
     audio = recognizer.listen(source)
     try:
+        # runs the live recored audio through PocketSphinx. Send the iterpreted audio as text to function trigger_action
         cmd = recognizer.recognize_sphinx(audio)
         print("Command: {}".format(cmd))
         trigger_action(cmd)