Add missed part to TemperatureSensor factory

Author: mcsakoff

README.rst

@@ -46,7 +46,7 @@ Get temperature when there is only one 1-wire device on the bus::
     from digitemp.master import UART_Adapter
     from digitemp.device import TemperatureSensor
 
-    sensor = TemperatureSensor(UART_Adapter('/dev/ttyS0')
+    sensor = TemperatureSensor(UART_Adapter('/dev/ttyS0'))
     sensor.info()
     print(sensor.get_temperature())
 

digitemp/__init__.py

@@ -1 +1 @@
-__version__ = '1.4.0'
+__version__ = '1.4.1'

digitemp/device/factories.py

@@ -3,15 +3,27 @@
 from ..exceptions import OneWireException
 from ..utils import *
 
+if PY3:
+    from typing import Optional
+
 __temperatureSensors = {
     0x10: DS18S20,
     0x22: DS1822,
     0x28: DS18B20,
 }
 
 
-def TemperatureSensor(bus, rom):
-    # type: (UART_Adapter, str) -> OneWireTemperatureSensor
+def TemperatureSensor(bus, rom=None):
+    """
+    If rom is not, will try to find a connected device.
+    In that case there must be only one device connected.
+    """
+    # type: (UART_Adapter, Optional[str]) -> OneWireTemperatureSensor
+    if rom is None:
+        roms = bus.get_connected_ROMs()
+        if len(roms) > 1:
+            raise OneWireException(f"More than one connected 1-wire device found: {', '.join(roms)}")
+        rom = roms[0]
     family_code = iord(str2rom(rom), 0)
     if family_code not in __temperatureSensors:
         raise OneWireException("Unsupported family code: %d" % family_code)