iFly GPS Forum

It sounds like you have it wired up correctly. So we could eliminate the iFly and cable as the problem, is there any way to test the serial data on your computer? You would need a terminal program of some sort that can read data from a serial port, and of course you would need a serial port on your computer (that is rare for new computers...but any USB to Serial cable would provide this capability).

If not, we could try replacing the serial cable. It's possible that is is defective; although I think this would be a first. But if a new cable didn't fix the issue we would at least remove that as a possible issue.

Sorry you are having this problem,
Walter

Dave,

We have lots of folks using this with EFIS systems, autopilots, fuel computers, etc. No reason it won't work with your system too.

The data is sent on Pin 3, trying Pin 2 would not serve a purpose. In fact connecting Pin 2 could make the connection more flaky. The iFly employs a sort of smart-switching system for the USB port. When you connect something it tries to detect the stream of data to figure out what to do with it. If there is no data, or it doesn't recognize the data, it allows the port to be used for as an NMEA output. We had one customer who connected the entire 9pins to his efis system, and there was some sort of data pump coming from that system which was confusing the switch, and the iFly would never configure the port for use as an NMEA output. He cut Pin 2 on the cable, then everything worked fine.

Because Alasdair actually sees the NMEA settings dialog when he goes to Setup / NMEA Output (which I've presumed from his first post), I know the port has been correctly detected and allocated within the iFly. I'm confident the data is being sent; I believe the problem is either the cable or the connection. One way or another, we'll get it fixed.

-Walter

Walter - Here's a question. The cable from the EFIS actually has all Pins 2,3 and 5 connected from the EFIS to the female DB9. The male cable I made to connect from that to my old GPS then intentionally physically only had pins 3 and 5 installed (as per my picture) - so there was absolutely no way pin 2 was connected between the two. However... for the ifly I didn't make that cable - you did ;-). So, I'd have to ask you what pins are actually hooked up in the cable you provide? Is it just 3 and 5 or is it simply an out of the box USB to serial adapter cable and likely they all connected including pin2? If so, maybe pin 2 is connected when using your cable after all and then reading between the lines from your reply to Dave, the connection may be 'flaky' as a result?

FYI - The reason the female DB9 on the EFIS end of the cable has 2,3 and 5 connected is that I occasionally need to unplug the GPS cable and then connect the EFIS to my PC for EFIS software updates (using another USB to serial adpater) which does require 2 way communication. For that reason I don't really want to cut pin 2 on the EFIS cable. Anway point being after reading your 'smart' USD port comment to Dave, IF your cable has all pins connected it could be for all I know receiving something from the EFIS . I could make a radio shack run and make up a short jumper cable male to female that definately only has pins 3 and 5 connected, put that between the two and give it a try - this would recreate my old cable set up regardless of what your cable actually has wired internally and ensure no possibility of there being a 'data pump' from the EFIS? Thoughts? Please let me know whats 'inside' your cable - it's not a connector that I could easily open up and take a peek at.

Thanks for getting the thinking process going again. Let me know!

Alasdair

P.S. I appreciate the help and am very impressed by the rapid responses you and your team make to these posts. Thank you - I know we'll figure it out.