Dynon Interconnect Issues

[PhantomPholly]

After repeated cycles of re-diagnosing intermittant connection issues between various Dynon units (and I've seen similar issues between components of other vendors), I've come to the conclusion that hard-wired solutions are simply a bad idea. My particular units are D180/HS34/EDC10A; but I'm pretty certain that others likely experience the same sorts of issues.

Suggestion for Dynon:  For nextgen, build in BlueTooth for all components.  I have come to believe that by now this is more reliable than these connectors.  Then test with avionics to insure that BlueTooth doesn't generate problamatic EMI.

 

[jakej]

Don't want to start a war BUT   the avionics industry have been using these Dsub connectors for years in all sorts of aircraft with TSO'd equipment and have proven to be totally reliable, and the best solution for 'connections' IMO.
I think the area of concern is poor wire preparation and crimping - using a good quality tool will reduce the probability of problems.  I recently found a situation where someone had crimped all his Dynon connection using a Molex type crimper (real bad idea) and consequently ALL those connections had to be redone.

Jake J

 

[PhantomPholly]

No provocation of war detected; however, I will stipulate that the wire crimping was NOT the issue.

Harness and female pins and D-Sub 9-pin connector end from Stein; hooked up the 9 pin connector originally using cheaper fold-over pins I already had.  Only 4 wires used, this is not rocket science.

Had issues, upgraded to barrel crimp pins from Stein:

...and got the nice $35 crimper, also from Stein:

Stripped using high-quality stripper, checked that all wire strands intact.  Stein harness wire gage was ideal for these pins - just barely fit into the barrel pin (had to use my reading glasses to insure no stray strands) and crimps were solid.

The only area of little "gripping force" was between the male and female pins, which bugged me a bit when I first assembled but I assumed that it was "enough."  Now I am not convinced, and removed each female pin; lightly squeezed; and re-inserted.  Now the connection requires noticeable force to insert.

Time will tell if this was truly the culprit.  Could be a micro-fracture on the circuit board, or could be the front connector, or could be an actual problem with the EFIS or remote compass.  Those latter, if intermittent, could be a bugger to nail down.

Bottom line:  Despite what I took to be great care twice (3 times if this fails), there were issues with reliable connectivity.  I do understand that it is worse with a serial connection device - if the remote compass quits in-flight you have to cycle the EFIS power to re-initialize (a very poor solution in my book!).  

As a separate suggestion, the system should be resistant to such a failure, and attempt automatically to re-start the remote device if communications is lost should happen automatically. Re-booting your PFD in flight is NOT a good solution.

 

[Brantel]

Are you sure you are using the correct barrels for the pins and vise versa??? There are different sizes of these things and it is not easy to see it visually. I think the color code is the best way to tell..

Millions of these connections are all over airliners and most if not all of the general aviation fleet...

It may be possible that you were using a barrel that was made for a bigger pin???  Or the barrel or pin was out of tolerance?

 

[dynonsupport]

The Dynon EFIS products DO NOT need a reboot to find the EDC. You can unplug and plug it back in as much as you want. If yours isn't acting that way, it's probably a hint as to what is wrong. Almost sounds like the processor in the EDC was locking up, and a reboot fixes that by killing the power to it. That could have been a bad power connection bouncing around.

We'll add bluetooth when they figure out how to transmit five watts of power over it Until then, you need wires for power anyway, so you might as well use wires for data too.

 

[jakej]

Great, Brantel & I agree ;D

Dynon's 'hint' as to what is wrong is more likely the case IMHO

Jake J

 

[dynonsupport]

Well, let me also say that it could be a bad EDC as well. One thing that his data is telling us is that it was not a simple case of the data wires becoming disconnected then re-connected, since the EFIS will recover from this with no issues.

 

[PhantomPholly]

Ok, re my response in a separate thread I only know of two sizes of barrel pins, and Dynon doesn't use the "Garmin" (thinner) pins - I tried, they are too small.

It was definitely not a crimp issue.  If there's a third pin size for D-Sub I haven't heard of it.  Will continue flying and see if it happens again.

Edit. Hmmm. Per Dynon's post the cpu lockup sounds more plausible. If it had lost power in flight due to bad connector, it is likely that at least ONE of the times I re-booted it would not have corrected the condition. Re-booting ALWAYS corrected the problem.

I'll fly with it a while longer and see if it recurs.