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KGT 05-15-2022 01:59 PM

FightDek 180 autopilot install won't work!
I recently installed new Dynon autopilot servos in my RV8 with a FlightDek 180 that I've used for 10 years. I ran the wires myself and am very confident it is wired correctly. The problem is the D180 doesn't recognize the servos. I was initially able to complete the set up process and everything appeared to work.

I went for a test flight and the autopilot worked for about 10 minutes then showed err message for both sevos as if power to the servos was turned off. However there is power to the servos. I did experience this same problem during initial setup but was able to finally get it to work. I checked continuity in the DSAB wires to the servo and they are good. I sent the FlightDek 180 in for the latest software update before the installation because they need the latest software to work with the new servos.

I'm out of ideas other than to send D180 or servos back to see if they can find anything. Dynon just had it last week I was hoping it would work since it was just updated!

Any suggestions would be appreciated. If I can't resolve this issue I may have new Dynon autopilot servos (SV32) and a used D180 for sale!


Carlos151 05-15-2022 08:31 PM

Just curious why you “sent in” your D180 for a software update? Dynon is pretty clear that you need to have ALL items on the DSAB bus connected and powered up at the same time for a software update. That includes servos, HS34, AP74, OAT sensor, heated pitot tube or any other Dynon items you may have. You can do the software update with a simple serial to USB cable connector. Looks to me like you may not have the same software operating on all of your Dynon equipment.
Take a look at chapter 7 and 8 of the Dynon installation guide. This may solve your problems.

“To ensure reliable operation, all Dynon devices should be upgraded to the same version of firmware; mismatched versions of firmware on different devices can cause unreliable operation.”

KGT 05-16-2022 04:11 AM

Dynon recommended update
Thanks for the reply. I spoke with Dynon prior to the installation I was told to update the D180. The new servos and the D180 theoretically have the same update version. I’ve read the installation manual as well and understand that part and went by Dynon’s recommendation.

drill_and_buck 05-16-2022 05:17 AM

Kevin, FWIW, passing along my experience with AP failure after firmware upgrade.... D-100 / D-120 with 400 hours of successful AP operations.

Last year I updated the firmware to all devices on the DSAB and tested the Autopilot in flight. It worked perfectly. When I went to restart the plane after landing, I got a DSAB error. The roll servo was no longer in the network. I tried several attempts to discover it without success.

An interesting point is that the Dynon Support Utility could discover the servo *and* update it's firmware. After the servo failure I updated the firmware once again. However, even after updating the firmware, I couldn't discover the servo from the Dynon AP menu to add it back into the network. Had to send the servo back to Dynon for repair. Received a new servo, AP now working as advertised.

s24789 05-16-2022 05:18 AM

We had an issue originally where the servos were not recognized by the bus master. Got new servos and all worked well. Explained the situation to Dynon and they replaced the servos.

KGT 05-16-2022 09:43 AM

Thanks all for the info! I purchased the servos recently from Aircraft Spruce maybe not the most recent update on them.


rondawes 05-16-2022 01:15 PM

Do you have an AP74? it has to have the same firmware as the D180. The servos have to have the same firmware as the D180. The latest version for the D180 is 5.6.1. You can connect your D180 to a PC and see the versions of all devices in the network and update them if needed.

You got the servos from AS so maybe they come with firmware for the Skyview series installed since that's the current model series Dynon sells? The Skyview uses a 4 wire network and the D180 the 2 wire DSAB network. The servos support both from a wiring perspective but I don't know if they have different firmware. I'd kind of bet they do.

KGT 05-17-2022 06:09 AM

No AP 74
As far as I know the servos are the same firmware with the Skyview and the D180. The Skyview uses two extra wires that aren’t hooked up with the D180 installation. I will pose the question next time I speak to Dynon tech. I am now unable to get the D180 to recognize the servos at all.


s24789 05-18-2022 07:34 AM

Another point I had forgotten was the power up sequence. When we had issues we would pull the cb to the servos and reset them and then the world worked well. We did not want to continue doing this so we installed a power interrupt momentary push button to kill and reapply power to the servos. The problem ultimately fixed itself and we removed the switch. A quick thing to try is the cb trick.

KGT 05-18-2022 12:17 PM

I have a circuit breaker switch for the servos so I can easily try the power up sequence trick and see if it helps.


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