I do not usually log research, in fact I think this is the first time. This will serve as my notes on the topic.
The D6 Dynon EFIS has one serial port. It can be used for two purposes. One purpose is to connect to a PC to download firmware upgrades etc. The other purpose is an input of GPS airspeed data that the D6 will use for attitude information if the pitot tube becomes blocked. If it is used as a backup airspeed indicator (groundspeed actually) it would connect to the yellow/grn wire that I have already installed in the Garmin 396 output line for that purpose.
The question is whether the one serial port can be used for both purposes by some means. I will have to contact Dynon and ask. I seem to remember a way in which that might be possible. It would probably require the removal of the GPS input connector while the PC download is taking place.
The backup power connection for the D6 will supply power only if the master switch (main) power is not present. Actually, in my setup the power comes from the avionics switch after the master switch. If the master failed, so would everything else downstream including the avionics switch and consequently the D6. So, where would that backup power lione connect? Any connection for it would be after the master switch. It is logical to put it after the master switch but before the avionics switch, in case the avionics circuit fails. There is an internal backup battery in any case, so I am not sure I will install the backup power wire.
Evening:
I can't do much with my hands tonight because I had surgery this afternoon to remove a basel cell from my right hand.
I emailed dynon today about the problem with the D6 serial input being needed for two purposes. I also researched on VAF and sent an email to Dick Isherwood about the problem.
I think the solution is to have a small switch that will switch the input to the D6 serial from GPS to PC wiring. I played with that tonight and cut a piece of light angle, just over 4 3/4 in long which can
