Simple ctypes wrapper for C library.

Author: nebulans

Adafruit_DHT_Driver/DHT_Wrapper.py

@@ -0,0 +1,29 @@
+import ctypes
+from decimal import *
+
+
+class DHT(object):
+    """
+    Wrapper for Adafruit DHT11/DHT22/AM2302 sensor Raspberry Pi driver.
+    """
+    def __init__(self, sensor, pin):
+        """
+        Initialize with sensor type as string and pin Raspberry Pi pin number as integer
+        """
+        self.DHTlib = ctypes.CDLL("./libAdafruit_DHT.so")
+        if not self.DHTlib.init():
+            raise IOError("Could not initialise BCM2835 - may need to run as root")
+        self.sensor = self.DHTlib.parseType(ctypes.c_char_p(sensor))
+        self.pin = ctypes.c_int(pin)
+        self.DHTlib.readDHT.restype = ctypes.POINTER(ctypes.c_float)
+    def read(self):
+        """
+        Returns a dict of decimals representing measured temperature and humidity
+        """
+        r = self.DHTlib.readDHT(self.sensor, self.pin, ctypes.c_int(0))
+        if r[1] > 0:
+            q = Decimal("0.1")
+            return {"temp": Decimal(r[0]).quantize(q), "hum":Decimal(r[1]).quantize(q)}
+        else:
+            return False
+