diff --git a/mapid.py b/mapid.py
index 058c4e3..91963ff 100644
--- a/mapid.py
+++ b/mapid.py
@@ -1,3 +1,8 @@
+"""MAPID utility library.
+
+This module contains an utility class to control MAPID/CP using pyserial.
+"""
+
 import os
 import time
 import dotenv  # 
@@ -5,8 +10,15 @@ import serial
 
 
 DOTENV_LOADED = False
+"""bool: Is .env loaded?
+
+Prevents loading .env multiple times for speed.
+"""
+
 
 def load_dotenv():
+	"""Load .env file
+	"""
 	basedir = os.path.abspath(os.path.dirname(__file__))
 	dotenv.load_dotenv(os.path.join(basedir, ".env"))
 	global DOTENV_LOADED
@@ -14,6 +26,12 @@ def load_dotenv():
 
 
 def get_serial_dev():
+	"""Get SERIAL_DEV setting from dotenv.
+
+	Returns:
+		str: The device file.
+
+	"""
 	global DOTENV_LOADED
 	if not DOTENV_LOADED:
 		load_dotenv()
@@ -21,6 +39,12 @@ def get_serial_dev():
 
 
 def get_serial_speed():
+	"""Get SERIAL_SPEED setting from dotenv.
+	
+	Returns:
+		int: Serial speed in baud.
+
+	"""
 	global DOTENV_LOADED
 	if not DOTENV_LOADED:
 		load_dotenv()