update

python/examples/test_servo_angle_cpp.py

+import time  
+from ctypes import *
+import ctypes 
+import cv2              
+                      
+so = ctypes.cdll.LoadLibrary   
+pwm = so("./libPCA9685.so")
+
+           
+def set_servo_angle(channel, angle):             
+    date=4096*((angle*11)+500)/20000              
+    pwm.setPWM(channel, int(date))  
+   
+def get_servo_angle(channel):  
+    date=pwm.getPWM(channel+1)       
+    angle=(20000*date - 500*11)/(4096*11) -45
+    print(str(channel) +':'+ str(int(angle)))  
+
+  
+# Set frequency to 50hz, good for servos.  
+pwm.setPWMFreq(50)  
+  
+print('Moving servo on channel x, press Ctrl-C to quit...')  
+while True:  
+    # Move servo on channel O between extremes. 
+    get_servo_angle(1)
+    get_servo_angle(2)
+    channel=int(input('pleas input channel:'))  
+    angle=int(input('pleas input angle:'))  
+    set_servo_angle(channel, angle)  
+    time.sleep(1)