Connecting PAW to external Garmin GPS via serial NMEA link

[peter843]

To avoid the complexity of fitting another GPS antenna, and to be able to utilise the best GPS antenna on the plane, I was wondering if I can feed my Garmin GTN650 or G3X GPS data into the PAW via a serial NMEA connection. Has anyone done this? Any idea which pins in the Garmin. Does PAW  decode NMEA directly?

Looking at the G3X install guide it's noted. "The G3X system can provide NMEA 0183 formatted GPS position data to an ELT, via an RS-232 output from a GDU display."
I wonder can the PAW use this same data stream, recieve only no handshake,  2 wire RS-232?

[PaulSS]

I'm sure I recall an old thread where they were talking about the ability to do this and, at the time, people were asking if it will ever be incorporated. That was something like a 2016 thread, so I would be willing to bet it has been.......but somebody knowledgeable will be along to confirm (Lee).

If an FTDI USB to RS232 converter works PAW to EFIS for traffic over the orange (Tx) wire + black ground, surely it would just be a matter of yellow wire (Rx) from the G3X Tx + black ground. I would imagine baud rates would need to be matched at as high a level as possible (57600) and Robert should be your Father's brother.

I will be interested (genuinely) to learn where my logic (ish) falls down.

[peter843]

Answering my own question. I did some experimentation. Removed the GPS dongle from USB port 1. Connected 2 wire TX to a RS-232 to USB adapter.  Configured PAW USB port 1 to GPS. Sent simulated 4800 baud NMEA data. The PAW decodes nicely.

[Admin]

Hi Peter
Good work
If you write up an apps note, we will include in our documents
Thx
Lee