Update README.md

README.md

 ## Description
 
-This node provides a system to detect and manage collisions using a [bno055 IMU](https://learn.adafruit.com/adafruit-bno055-absolute-orientation-sensor).
+This node provides a system to detect and manage collisions using a [bno055 IMU](https://learn.adafruit.com/adafruit-bno055-absolute-orientation-sensor) connected with an [USB to TTL serial cable](https://www.mouser.es/ProductDetail/Adafruit/954?qs=GURawfaeGuBg0XxCeRWeUA==).
 
 This node also provides the following configuration files located in [config](./config) directory:
   * **params.yaml**: Node default configuration file.