rx data should be char rather than unsigned char

README.md

@@ -31,7 +31,7 @@ if hackrf.is_open == False:
     hackrf.set_baseband_filter_bandwidth(1 * 1000 * 1000)  
 
 def callback_fun(hackrf_transfer):
-    array_type = (ctypes.c_ubyte*length)
+    array_type = (ctypes.c_byte*length)
     values = ctypes.cast(hackrf_transfer.contents.buffer, ctypes.POINTER(array_type)).contents
     #iq data here
     iq = hackrf.packed_bytes_to_iq(values)    

examples.py

@@ -0,0 +1,20 @@
+import pylibhackrf ,ctypes
+
+hackrf = pylibhackrf.HackRf()
+
+if hackrf.is_open == False:
+    hackrf.setup()
+    hackrf.set_freq(100 * 1000 * 1000)
+    hackrf.set_sample_rate(8 * 1000 * 1000)
+    hackrf.set_amp_enable(False)
+    hackrf.set_lna_gain(16)
+    hackrf.set_vga_gain(20)    
+
+def callback_fun(hackrf_transfer):
+    array_type = (ctypes.c_byte*length)
+    values = ctypes.cast(hackrf_transfer.contents.buffer, ctypes.POINTER(array_type)).contents
+    #iq data here
+    iq = hackrf.packed_bytes_to_iq(values)    
+    return 0
+
+hackrf.start_rx_mode(callback_fun)

pylibhackrf.py

@@ -80,7 +80,7 @@ class hackrf_device(Structure):
 
 class hackrf_transfer(Structure):
         _fields_ = [("hackrf_device", POINTER(hackrf_device)),
-                ("buffer", POINTER(c_uint8)),
+                ("buffer", POINTER(c_byte)),
                 ("buffer_length", c_int),
                 ("valid_length", c_int),
                 ("rx_ctx", c_void_p),
@@ -523,8 +523,7 @@ class HackRf(object):
         # use NumPy array
         iq = np.empty(len(bytes)//2, 'complex')
         iq.real, iq.imag = bytes[::2], bytes[1::2]
-        iq /= (255/2)
-        iq -= (1 + 1j)
+        iq /= 128.0
         return iq
 
     def packed_bytes_to_iq_withsize(self, bytes, size):
@@ -535,6 +534,5 @@ class HackRf(object):
         iq = np.empty(size , 'complex')
         bytes2 = bytes[0:size * 2]
         iq.real, iq.imag = bytes2[::2], bytes2[1::2]
-        iq /= (255/2)
-        iq -= (1 + 1j)
+        iq /= 128.0
         return iq