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AP74 Track Problem

J

JohnF

Well Known Member
I suspect somehow the problem below is something I am not doing correctly, but here goes anyway:

The autopilot altitude hold works fine; the heading feature works fine, the "value" know works to set barometer and heading fine; the red buttom to disconnect everything works fine, the system recognizes all Dynon units (4) but I cannot get the a/p to track a flight plan from the Garmin 396. The flight plan is loaded and seems normal, but the light for the TRK or tracking feature does NOT light up when the button is depressed as the other selections do.

I posted a similiar post on the Dynon company web site,

Ideas?
 
To have your AP follow a GPS flight plan, you must be in NAV mode. TRK is for following a GPS ground track.

That being said, you should be able to press TRK at any time and follow the GPS ground track as long as your airspeed is between the min and max value you have set up.

What does your HSI look like when you are trying to do this? Is it magenta in color? Are you sure that your GPS is talking to the D180? Are you getting the wind arrow etc? Does your course pointer always point to North/360°? (it should not if working correctly).

To fully function, your GPS's Advanced NMEA speed setting must be set to "Normal" and not "Fast". If it is set to FAST, some functions will work and some won't.

Here is a pic of what your HSI should look something like if you have the GPS communicating correctly and you have a waypoint active in a flight plan on the GPS...

d100%20two_third%20efis%20one_third%20hsi_full.gif


If your HSI does not work correctly, neither will the AP.
 
Last edited:
Track or Nav??

John:

If you are trying to get the Dynon to navigate a course you have programmed into the Garmin, you use the Nav button on the AP74 and not the Track button. Have you tried Nav?

Now, having said this, Track should also be functional on your AP74, with or without a flight programmed into the Garmin. Not clear why you would not be getting it to light up at all. If neither Nav nor Track work, then I would wonder about communications between the Garmin and Dynon. Are other Dynon features that rely on communication with the Garmin working (e.g. the windspeed and direction arrow, navigation screen on the Dynon showing GPS as the Nav source, etc)?

Jeff
 
oops

Ok- was typing as Brantel sent his reply. His is much more thorough- picture and everything!!!

Jeff
 
That photo is overwhelming to a person not used to viewing the D180. I am not sure I can ever figure out what all those symbols and readings are for.
 
Don,

It will come to you...You can turn stuff on and off to your liking...That pic pretty much shows everything + the HSI.

Here is an example of how minimalistic you can make it:

D100frontview.jpg


You can even take it further and remove stuff like the AOA bar..

Note that this shows the "Classic" display mode, you can switch between classic and modern....

DonFromTX said:
That photo is overwhelming to a person not used to viewing the D180. I am not sure I can ever figure out what all those symbols and readings are for.
Click to expand...
 
Not all that hard

Don:

I learned to fly in a 1976 C-150 and 1972 C-172, both with steam gauges and until I finished the -12, had never flown behind a glass panel. It looks overwhelming at first but I have to say that after only a few hours, I was very comfortable with it. It is really an easy adjustment!

Jeff
 
AP74 Problem

Yes, Brantel and the other responders...its appears that there is a communication problem between the Garmin (I hate that thing!) and the AP. Will look into that....not certain what that min and max setting is, but will look further...thanks you folks !
JohnF
 
Check coax shield at ELT

The GPS RS232 output (blue wire) goes to 3 places: SL40 com radio pin 10, Dynon D-180 EMS pin 19, and ELT (Spliced to blue wire). If that wire gets shorted to ground, then none of the above 3 units will communicate with the GPS. The most likely place for a short to ground to occur is at the ELT. The wire that goes there looks like a plain white wire, but is actually a coaxial cable. Some builders are not aware of that and fail to isolate the coax shield from the center conductor. If your GPS is not communicating, check the connection at the ELT.
Joe
 
AP74 Problem

Thanks, Mitch, I will check that coax in the morning. It seems I have a definite communications problem...the HSI display is NOT being shown in magenta as it should be, and in the Dynon Install manual on page 8-24, it says, "In EFIS/AP/mode menu that BOTH HDG and TRK options should be displayed. The TRK is not being displayed.

I am pulling the cover over the inst panel to check more tomorrow.

Thanks for the hint (I hope you're right because it would be an easy fix)

JohnF
 
ELT end of the Coax

JohnF,
There is no need to remove the instrument panel cover, yet. First check the other end of the coax at the ELT behind the passenger seat.
Joe
 
AOA

I Noted On Brantel's HSI that he had a AOA showing so I Asume he has a RV 7. My Question is has any RV 12 owners been able to install the Dynon AOA / AS Pipot Installation thro the Prop & Spinner of the RV 12..? Thanks for you answers Guys!
 
I just used a stock image from Dynon's site. While I think it would be possible to use the Dynon to display AOA for the 12, the 12 is a special case. It could be done though. I think it is Mel that has made his own AOA proble and his methods could be ported to making one for the 12.

splitty said:
I Noted On Brantel's HSI that he had a AOA showing so I Asume he has a RV 7. My Question is has any RV 12 owners been able to install the Dynon AOA / AS Pipot Installation thro the Prop & Spinner of the RV 12..? Thanks for you answers Guys!
Click to expand...
 
Dont Quote me!

Im not 100% sure but I believe there is a EAB RV12 here in the states that does have the angle of attack option on it, but the owner had to mount another traditional Pitot tube on the wing. I don't think you could do one through the Prop.
 
John,

Didn't see it mentioned yet, and you may have already covered this with Brian (Brantel) in your PMs, but if the -12 has a disconnect switch on blue wire between the Garmn and the Dynon (to allow for firmware updates), perhaps check that it's in the on position. I have forehead slappers like that from time to time, so thought I'd pass it along.

Hope you get to the solution soon!!

Cheers,
Bob
 
AP74 Problem SOLVED

I resolved the non-communication between the Garmin GPS and the Dynon autopilot.

I checked the WHF55 white wire with GPS information that ends up at the ELT to confirm if the shield braid of that micro-coaxial cable might have been shorted to the inner conductor...bad light so couldn't be positive but likely it was shorted...pulled back the braid and put heat shrink on it to insure no short. Likely was shorted.

But that didn't clear up the problem. Seems there were two problems.

The second on took a lot of button pushing to resolve but this is the sequence of button pushing on the Dynon D180 that led to the solution.

EFIS/MORE/SETUP/MORE/MORE/MORE/HSI/EFIS-EMS SERIAL /INPUT-NMEA/ BAUD RATE AUTO. The baud rate had been at 9600, when set to AUTO everything at the autopilot began to work.

Thank you for the assistance, RV'ers !

JohnF
 
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