bluetooth programming for unity 3d

Question

I have a sensor and a Bluetooth dongle( HC 05) with SPP protocol. We have to connect the sensor to the PC via Bluetooth in which we made ourgame in unity 3D. The problem now is i have to write a program for the Bluetooth so that 1)unity search for the sensor ( the sensor will be having a mac address and we will be having 5 sensors, other than those 5 sensors it will not allow any other sensor to be paired with, it will reject the pairing). 2) after searching for the sensor it will start pairing with PC in whichour unity is installed. i have to write Bluetooth programming, i only know a little bit of C language only. I tried searching online but the programming is for Bluetooth API for android only. I am new to this problem, so please help me from the basics. It would beof great help. Thank you.