Update ReadMe.md

ReadMe.md

@@ -24,6 +24,18 @@ This driver offers a c++ wrapper to control a [dynamixel servo](http://www.robot
 
 ``` sudo apt update && sudo apt install iri-dynamixel-motor-cont-dev ```
 
+## Important information
+
+To use this driver is necessary to unload the *ftdi_sio* module, so the device is detected as a serial-usb device.
+This can be achieved with the following command
+   
+   ```sudo rmmod ftdi_sio```
+    
+or executing the following script:
+
+   ```unbind_ftdi_udev.sh -s <serial_number>```
+
+
 ## Disclaimer  
 
 Copyright (C) 2009-2019 Institut de Robòtica i Informàtica Industrial, CSIC-UPC.