diff --git a/sht21.py b/sht21.py
index c93372d..2af4e54 100755
--- a/sht21.py
+++ b/sht21.py
@@ -32,27 +32,27 @@ def __init__(self, device_number=0):
         loaded).  Note that this has only been tested on first revision
         raspberry pi where the device_number = 0, but it should work
         where device_number=1"""
-        self.i2c = open('/dev/i2c-%s' % device_number, 'r+', 0)
+        self.i2c = open('/dev/i2c-%s' % device_number, 'rb+', 0)
         fcntl.ioctl(self.i2c, self.I2C_SLAVE, 0x40)
-        self.i2c.write(chr(self._SOFTRESET))
+        self.i2c.write(bytes([self._SOFTRESET]))
         time.sleep(0.050)
 
     def read_temperature(self):    
         """Reads the temperature from the sensor.  Not that this call blocks
         for ~86ms to allow the sensor to return the data"""
-        self.i2c.write(chr(self._TRIGGER_TEMPERATURE_NO_HOLD))
+        self.i2c.write(bytes([self._TRIGGER_TEMPERATURE_NO_HOLD]))
         time.sleep(self._TEMPERATURE_WAIT_TIME)
         data = self.i2c.read(3)
-        if self._calculate_checksum(data, 2) == ord(data[2]):
+        if self._calculate_checksum(data, 2) == data[2]:
             return self._get_temperature_from_buffer(data)
 
     def read_humidity(self):    
         """Reads the humidity from the sensor.  Not that this call blocks 
         for ~30ms to allow the sensor to return the data"""
-        self.i2c.write(chr(self._TRIGGER_HUMIDITY_NO_HOLD))
+        self.i2c.write(bytes([self._TRIGGER_HUMIDITY_NO_HOLD]))
         time.sleep(self._HUMIDITY_WAIT_TIME)
         data = self.i2c.read(3)
-        if self._calculate_checksum(data, 2) == ord(data[2]):
+        if self._calculate_checksum(data, 2) == data[2]:
             return self._get_humidity_from_buffer(data)
 
     def close(self):
@@ -75,7 +75,7 @@ def _calculate_checksum(data, number_of_bytes):
         crc = 0
         # calculates 8-Bit checksum with given polynomial
         for byteCtr in range(number_of_bytes):
-            crc ^= (ord(data[byteCtr]))
+            crc ^= data[byteCtr]
             for bit in range(8, 0, -1):
                 if crc & 0x80:
                     crc = (crc << 1) ^ POLYNOMIAL
@@ -90,7 +90,7 @@ def _get_temperature_from_buffer(data):
         T = -46.85 + (175.72 * (ST/2^16))
         where ST is the value from the sensor
         """
-        unadjusted = (ord(data[0]) << 8) + ord(data[1])
+        unadjusted = (data[0] << 8) + data[1]
         unadjusted &= SHT21._STATUS_BITS_MASK  # zero the status bits
         unadjusted *= 175.72
         unadjusted /= 1 << 16  # divide by 2^16
@@ -104,7 +104,7 @@ def _get_humidity_from_buffer(data):
         RH = -6 + (125 * (SRH / 2 ^16))
         where SRH is the value read from the sensor
         """
-        unadjusted = (ord(data[0]) << 8) + ord(data[1])
+        unadjusted = (data[0] << 8) + data[1]
         unadjusted &= SHT21._STATUS_BITS_MASK  # zero the status bits
         unadjusted *= 125.0
         unadjusted /= 1 << 16  # divide by 2^16
@@ -134,9 +134,9 @@ def test_checksum(self):
 
 if __name__ == "__main__":
     try:
-        with SHT21(0) as sht21:
-            print "Temperature: %s" % sht21.read_temperature()
-            print "Humidity: %s" % sht21.read_humidity()
-    except IOError, e:
-        print e
-        print "Error creating connection to i2c.  This must be run as root"
+        with SHT21(1) as sht21:
+            print("Temperature: %s" % sht21.read_temperature())
+            print("Humidity: %s" % sht21.read_humidity())
+    except IOError as e:
+        print(type(e), e)
+        print("Error creating connection to i2c.  This must be run as root")