More on the 5.3 firmware upgrade...
This turned out to be very easy, with one minor showstopper. I had the top fuselage cover off for the DAR inspection, so took advantage of that to do the Service Bulletin regarding the dual display wiring. Very easy, cut and cap two wires, and pull their two pins out of the D100 D-sub and install the little data upgrade harness by pushing in 3 pins. Altitude output on the transponder now works. People getting newer Avionics Kits will probably not have to do this.
Upgraded the D180 to firmware 5.3 using the laptop. The Dynon support program asks if you have downloaded Van's locked settings file. You need a locked settings file for both the D180 and the D100. If so you then point to it's location on your computer and the upgrade starts. Takes a little while, lots of little chips to reprogram, I guess. Then started the upgrade on the D100, which stopped with the message "Magnetometer not found". Since I have a Mag, I called Dynon support. The message is for if you have a Mag hooked up to the D100, which you don't. So, you OK this message and continue. No problem if you understand.
A USB extension cable is useful so you can place the laptop on a blanket on the wing, or if you are hooking up to a desktop computer on a stand next to the plane.
This is an excellent time to make a backup copy of your firmware installation, which will preserve your checklists and especially your fuel tank calibration and any other settings you may have programed, if for any reason the D180 goes down and has to be resurrected from the dead.
All in all, this was an easy upgrade.
Tony