I'm just after one way - Pin 3 is EFIS receive/GPS NMEA output, Pin 5 Ground. The cable I had previously made up for my Lowrance worked fine. As shown in the picture below I had actually only installed pins 3 and 5 in the plug on that one. It was purely one way GPS Tx / EFIS Rx on Pin 3.
It read as if your cable would provide exactly the same. GPS NMEA out on Pin 3, ground on Pin 5. That should be all I need - just doesn't work. To clarify your question regarding bi-directional, per the EFIS manual EFIS output to Nav/GPS is on Pin 2 not three and as you can see from the above picture I didn't even bother installing a Pin 2 on my last set-up so I honestly don't think that's the issue.
FWIW when it didn't work, I temporarily reconnected the old GPS with the above pictured cable and it works fine. So I conclude that either (i) ifly is not sending data or (ii) the cable doesn't work..?
I'd like it to work as my Dynon EFIS is also the autopilot and it used to happily follow the GPS around!
The Lowrance was set to 9600 baud and the following sentences (everything it offered) were on - GLL, GGA, APX,RMC&RMS, GSA&GSV
Dynon manual is here www.dynonavionics.com/downloads/Insta... See page 10 for wiring harness. You'll see the DB9 connector for serial port or GPS input on Pin 3.
Any help/ideas greatly appreciated.