Just my two cents, but I did have a learn-able user error moment I want to share regarding my last firmware update. I actually did make many mistakes which I will document so we can all learn. Goods news is no one was hurt, no damage was done and much was learned thanks to Ralph over at FlyhighUSA.com.
It seems my AC does not do the expected firmware lights or beeps. It does not beep before or after it is done. And during the upgrade process, the tail light only flashes yellow fast (not connected to RC) .The only thing I think is a sign that something is happening is the camera will flash it's LED green/red for a while then stop at some point. And there are what sounds like a servo that change and may indicate an upgrade is in progress. Also, the battery lights seem to dim the top and bottom battery lights during battery upgrade followed by going dark then all on when done (which I only noticed when upgrading all the batteries with 1.8 on the SD in the AC).Lastly, after what looks like a successful AC upgrade (or downgrade), there is no version text file on the SD card. The only way to check the version is through the DJI Go App. Weird? Next upgrade I will use a different SD card.
Based on my misconception of the upgrade lights/sounds, here is what I think may have happened; I actually interrupted the AC update process without the correct beeps and lights to guide me (and user error in that I rushed and didn't confirm). Then the DJI Go App offered to upgrade the RC and I accepted but didn't restart and flew Monday. So the RC/AC worked Monday for my test flights. Thursday, after a power cycle of the RC I had the firmware mismatch that triggers the "Lost RC Signal." Just a guess.
Either way with Ralph's help I downgraded all then upgraded all properly. Here are some other misc tips I picked up in this lesson:
- Generally turn on RC first then AC. If you turn on AC first it's radios are on are listening leaving them open for inadvertent connections to devices other than your RC.
- When upgrading, update AC first then RC. When Downgrading, order not as important.
- Always read firmware update notes before upgrading. They may change upgrade process. For example, summer 2015 they changed the method for upgrading the RC. No longer able to upgrade RC with a USB stick. Use DJI App to upgrade RC.
- When downloading firmware, go to your specific I1 product download page. I recently switched from an I1 to an I1 Pro and had never bothered to go get the Pro download.
- to upgrade or downgrade the AC firmware, With remote off, have a exFat32 formatted completely empty (no hidden files or folders) with only the upgrade bin file of the version being upgraded or downgraded.
- Yes, you have to upgrade each battery with that same bin file unless the release notes say otherwise.
I think that last part is important. This isn't mass consumer software and the publisher probably reserves the right to change any and all of it. Read the release notes. Read the release notes. Something I admit I rarely do with any consumer electronics or desktop software.