cpu temp as float, extend rpi (#5)

* cpu temp as float, extend rpi

* replace defaults with None value

Author: sky3d

Diff for: README.md

@@ -3,6 +3,13 @@ Cloud4RPi Examples for [Raspberry Pi](https://www.raspberrypi.org/products/)
 
 [![Build Status](https://travis-ci.org/cloud4rpi/cloud4rpi-raspberrypi-python.svg?branch=master)](https://travis-ci.org/cloud4rpi/cloud4rpi-raspberrypi-python)
 
+This example demonstrates different scenarios of using Cloud4RPi service on Raspberry Pi:
+ - Monitoring events
+ - Controling a GPIO pin
+ - Monitoring temperature with the DS18B20 sensor
+
+For complete instructions on how to run this example, refer to the [How To](https://cloud4rpi.github.io/docs/howto/rpi) article.
+
 ## Running the Sample Code
 
 1. Update your system and make sure you have the latest versions of all required software:

Diff for: control.py

@@ -1,35 +1,12 @@
 # -*- coding: utf-8 -*-
-#
-# Cloud4RPi Example for Raspberry Pi
-# ==================================
-#
-# This example demonstrates different scenarios of using Cloud4RPi service
-# on Raspberry Pi:
-#
-# - Monitoring events
-# - Controling a GPIO pin
-# - Monitoring temperature with the DS18B20 sensor
-#
-# For complete instructions on how to run this example, refer
-# to the [How To](https://cloud4rpi.github.io/docs/howto/) article.
-#
-# The DS18B20 sensor should be connected as follows:
-#
-#  / GND |────────────> GND
-# | DATA |─────────┬──> GPIO4
-#  \ VCC |─┬─[4k7]─┘
-#          └──────────> 5V
-#  DS18B20 (bottom view)
-
-from os import uname
-from socket import gethostname
+
 import sys
 import time
 import random
-import RPi.GPIO as GPIO  # pylint: disable=F0401
 import cloud4rpi
 import ds18b20
 import rpi
+import RPi.GPIO as GPIO  # pylint: disable=F0401
 
 # Put your device token here. To get the token,
 # sign up at https://cloud4rpi.io and create a device.
@@ -99,8 +76,8 @@ def main():
     diagnostics = {
         'CPU Temp': rpi.cpu_temp,
         'IP Address': rpi.ip_address,
-        'Host': gethostname(),
-        'Operating System': " ".join(uname())
+        'Host': rpi.host_name,
+        'Operating System': rpi.os_name
     }
 
     device = cloud4rpi.connect(DEVICE_TOKEN)

Diff for: ds18b20.py

@@ -1,5 +1,14 @@
 # -*- coding: utf-8 -*-
 
+# The DS18B20 sensor should be connected as follows:
+#
+#  / GND |────────────> GND
+# | DATA |─────────┬──> GPIO4
+#  \ VCC |─┬─[4k7]─┘
+#          └──────────> 5V
+#  DS18B20 (bottom view)
+#
+
 import os
 import re
 import subprocess

Diff for: rpi.py

@@ -1,27 +1,35 @@
 # -*- coding: utf-8 -*-
 
+from os import uname
+from socket import gethostname
 import subprocess
 import re
 
 
-def parse_output(pattern, default, args):
+def parse_output(pattern, args):
     try:
         out_str = subprocess.check_output(args)
         if isinstance(out_str, bytes):
             out_str = out_str.decode()
     except Exception:
-        out_str = 'error'
+        out_str = ''
+
     match = re.search(pattern, out_str)
-    if match:
-        result = match.group(1)
-    else:
-        result = default
-    return result
+    return match.group(1) if match else None
 
 
 def cpu_temp():
-    return parse_output(r'temp=(\S*)\'C', '0', ['vcgencmd', 'measure_temp'])
+    t_str = parse_output(r'temp=(\S*)\'C', ['vcgencmd', 'measure_temp'])
+    return float(t_str) if t_str else None
 
 
 def ip_address():
-    return parse_output(r'(\S*)', '?', ['hostname', '-I'])
+    return parse_output(r'(\S*)', ['hostname', '-I'])
+
+
+def host_name():
+    return gethostname()
+
+
+def os_name():
+    return " ".join(uname())