From cec86d65a5b80bcfaf447ff078031d92ed3c7557 Mon Sep 17 00:00:00 2001
From: Cody Hiar <codyfh@gmail.com>
Date: Wed, 16 May 2018 20:58:25 -0600
Subject: More script cleanup

---
 temp.py | 63 +++++++++++++++++++++++++++++++++++++++------------------------
 1 file changed, 39 insertions(+), 24 deletions(-)

diff --git a/temp.py b/temp.py
index 865faa7..eb0ecf4 100644
--- a/temp.py
+++ b/temp.py
@@ -1,29 +1,35 @@
+#!/usr/bin/python3
 # -*- coding: utf-8 -*-
-"""Python script to read temperature.
+"""Python script to read temperature from DS18B20.
 
 I plug the sensor data into pin 4 on the raspberry pi which requires pin 4 to
 be a gpio pin. If the modprobe commands don't results in the device showing up
-in the bus folder then make sure the following line is in `/boot/config.txt`
+in the bus folder then make sure the following line is in `/boot/config.txt`:
 
 ```
 dtoverlay=w1-gpio,gpiopin=4
 ```
 
-After rebooting the files should show up.
+After rebooting and the script should work.
 """
 import glob
 import os
 import time
 
-os.system('modprobe w1-gpio')
-os.system('modprobe w1-therm')
+def enable_kernel_modules():
+    """Enable kernel modules."""
+    os.system('modprobe w1-gpio')
+    os.system('modprobe w1-therm')
 
-base_dir = '/sys/bus/w1/devices/'
-device_folder = glob.glob(base_dir + '28*')[0]
-device_file = device_folder + '/w1_slave'
+def get_device_file():
+    """Get the path to the the data file."""
+    base_dir = '/sys/bus/w1/devices/'
+    device_folder = glob.glob(base_dir + '28*')[0]
+    device_file = device_folder + '/w1_slave'
+    return device_file
 
 
-def read_temp_raw():
+def read_device_file(device_file):
     """Read the raw temperature from the device."""
     f = open(device_file, 'r')
     lines = f.readlines()
@@ -31,20 +37,29 @@ def read_temp_raw():
     return lines
 
 
-def read_temp():
-    """Read the temperature of the probe."""
-    lines = read_temp_raw()
-    while lines[0].strip()[-3:] != 'YES':
-        time.sleep(0.2)
-        lines = read_temp_raw()
-        equals_pos = lines[1].find('t=')
-        if equals_pos != -1:
-            temp_string = lines[1][equals_pos+2:]
-            temp_c = float(temp_string) / 1000.0
-            temp_f = temp_c * 9.0 / 5.0 + 32.0
-            return temp_c, temp_f
+def parse_raw_input(raw_input):
+    """Parse raw data into temperatures."""
+    # Error reading, return nothing
+    if raw_input[0].strip()[-3:] != 'YES':
+        return None, None
+    equals_pos = raw_input[1].find('t=')
+    if equals_pos != -1:
+        temp_string = raw_input[1][equals_pos+2:]
+        temp_c = float(temp_string) / 1000.0
+        temp_f = temp_c * 9.0 / 5.0 + 32.0
+        return temp_c, temp_f
+    else:
+        return None, None
 
+def main():
+    """Main Function."""
+    enable_kernel_modules()
+    device_file = get_device_file()
+    while True:
+        raw_input = read_device_file(device_file)
+        print(parse_raw_input(raw_input))
 
-while True:
-        print(read_temp())
-        time.sleep(1)
+
+if __name__ == '__main__':
+    """Run main routine."""
+    main()
-- 
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