The FlightDEK-D180 will display HSI information generated by the GPS's couse when connected. You'll need to connect any of the GDU370's serial ports to one of the D180's serial ports as described in the manuals. When setting up the serial port on the 370, select the "Aviation In/NMEA & VHF Out" option. You can leave the D180 set to auto. Refer to your Dynon and Garmin installation/pilots manuals for more details, and give us a call at 425-402-0433 if you need a little more personal assistance.