controller/drivers/onewire/__init__.py

@@ -5,8 +5,15 @@ def read_one_thermo(filename):
     textfile = open(filename, 'r')
     filetext = textfile.read()
     textfile.close()
-    matches = re.findall("t=(\d+)", filetext)
-    return int(matches[0][0:-NO_OF_DECIMALS]) + (int(matches[0][-NO_OF_DECIMALS:]) / 1000.0)
+
+    matches = re.findall("t=(\-?)(\d+)", filetext)
+    sign = -1 if matches[0][0] == '-' else 1
+    whole_reading = matches[0][1]
+    first_part = matches[0][1][0:-NO_OF_DECIMALS]
+    second_part = matches[0][1][-NO_OF_DECIMALS:]
+    first_part = '0' if first_part == '' else first_part
+
+    return  (int(first_part)  +  (int(second_part) / (10.0 ** NO_OF_DECIMALS) )) * sign
 
 def read_many_thermo(filenames):
     result = []