diff --git a/gex/__init__.py b/gex/__init__.py
index 5c45986..023e08a 100644
--- a/gex/__init__.py
+++ b/gex/__init__.py
@@ -15,6 +15,7 @@ from gex.units.Neopixel import Neopixel
 from gex.units.I2C import I2C
 from gex.units.SPI import SPI
 from gex.units.USART import USART
+from gex.units.OneWire import OneWire
 
 
 # General, low level
diff --git a/gex/transport.py b/gex/transport.py
index 8c2000d..d747d34 100644
--- a/gex/transport.py
+++ b/gex/transport.py
@@ -193,8 +193,8 @@ class TrxRawUSB (BaseGexTransport):
         # Using time.sleep() would block for too long. Instead we release the semaphore on each Rx chunk of data
         # and then check if it's what we wanted (let TF handle it and call the listener)
         start = time.time()
-        while time.time() - start < timeout:
-            self.dataSem.acquire()
+        while (time.time() - start) < timeout:
+            self.dataSem.acquire(True, 0.1)
             if testfunc is None or testfunc():
                 break
         pass
diff --git a/gex/units/OneWire.py b/gex/units/OneWire.py
new file mode 100644
index 0000000..deb2633
--- /dev/null
+++ b/gex/units/OneWire.py
@@ -0,0 +1,12 @@
+import gex
+
+class OneWire(gex.Unit):
+    """
+    Dallas 1-Wire master
+    """
+
+    def _type(self):
+        return '1WIRE'
+
+    def test(self):
+        return self._query(0x00)
diff --git a/main.py b/main.py
index c6229ce..6ea4e35 100644
--- a/main.py
+++ b/main.py
@@ -12,6 +12,16 @@ with gex.Client(transport) as client:
         print(s)
         client.ini_write(s)
 
+    if True:
+        ow = gex.OneWire(client, 'ow')
+        resp = ow.test()
+        print(resp)
+
+        pp = gex.PayloadParser(resp.data)
+        print("Temperature   %f" % (pp.i16()/2))
+        print("Count_remain  %d" % pp.u8())
+        print("Count_per_deg %d" % pp.u8())
+
     if False:
         buf = client.bulk_read(gex.MSG_INI_READ)
         print(buf.decode('utf-8'))
@@ -105,7 +115,7 @@ with gex.Client(transport) as client:
         while True:
             client.poll()
 
-    if True:
+    if False:
         print(client.ini_read())
 
         trig = gex.DIn(client, 'trig')