X9D+ No Longer Logging Telemetry

[JBWingnut]

I went to check the telemetry log after a recent flight, and discovered that my transmitter has not been recording logs for the past couple of weeks (probably a couple dozen flights on three or four airplanes). Logging had been working perfectly for a couple of years until suddenly it didn't. I've spent a lot of time over the past few days trying to get it to start recording logs again, with no luck. I've provided the details of the situation below. I've tried everything I can think of to get logging working again, and have run out of ideas. It's probably something simple stupid that I've just overlooked. Any suggestions on what to try next would be appreciated...

Indications:
1. The only thing that changed since the logging ceased is that I did some minor programming changes on ONE of my models. I added a "suedo-lap counter" display for pylon racing, that uses global variables to count and display full-elevator pulls. I have not touched programming on any of my other models in months.
2. I currently have no logging on ANY of my models. I use 8XR, 6SR, 4XR, S6R, and S8R receivers on the various airplanes.
3. Logging is enabled via Special Functions and Logical Switches: Logging is supposed to begin when the motor is armed using Switch F aft.
4. The transmitter receives and displays real-time telemetry data.
5. The "SD card writing" indicator/icon is displayed on the transmitter screen when the logging should be occurring.
6. All other functions appear to work correctly on all my models/airplanes, including throttle arming, flight controls, rates, expo, etc.
7. I have never opened the case of the transmitter in the two years I have had it, and it has never been dropped or abused. I replaced the battery three or four months ago. I keep the transmitter in a Taranis soft case.

Things I've Tried That Didn't Resolve The Problem:
1. I made sure all my Sensors listed on the Companion Telemetry page were checked (for all my models)
2. I re-checked the throttle arming and logging logic in Logical Switches and Special Functions, and confirmed operation in the Companion simulator using the Logical Switches, Special Functions, and Global Variables windows.
3. I went through each of my airplanes, running them, to make sure they all functioned properly, and to confirm they all have the logging problem.
4. I changed my logging logic to a simple on/off switch independent of throttle arming.
5. I checked the SD card slot for dust and foreign objects, and proper operation of the spring-loaded card insert/removal mechanism.
6. I checked the capacity of my SD card (1GB card that has only used 300Mb)
7. I inserted the SD card into my computer to ensure all the files are really there, and can be accessed.
8. I transferred all the SD files onto a new SD card, and put the new card into the transmitter.
9. I reverted to a two-month-old EEPROM file backup of all my models (I know for sure everything was working back then)
10. I updated the firmware to version 2.2.2 (I had been running 2.2.1)

[pmullen503]

Check your RTC battery. I had the same problem, tried all the things you listed. Replacing the battery fixed it

[JBWingnut]

Oh, man... That would be a great solution! Anything I need to know before I pull the RTC battery out? Will the transmitter lose any internal data? Will I have to re-load the firmware? Or is it as simple as popping out the old battery and putting the new one in?

[Kilrah]

The only thing it holds is the time and date, nothing special needed when replacing.

[jhsa]

Make sure you remove the radio's main battery before you open it.. This is important, do not skip it..

João

[JBWingnut]

VICTORY!!! Thanks SO much, pmullin! I had about driven myself crazy trying to figure this out. Replacing the RTC battery did the trick. One bit of data to post for posterity, in case anyone else has this problem and comes across this post: The RTC battery size is LR 1220, 3V Lithium. The measured voltage of the old battery I removed was 3.04V. The measured voltage of the new battery I put in is 3.32V. If someone has this problem and measures the voltage of their battery, be advised that 3 volts on a 3 volt battery is not enough! Also, my transmitter is 2 years old... so that's how long my RTC battery lasted. Anyone with a transmitter that old should have an extra RTC battery in their flight box!

Thanks again!

[JBWingnut]

Well, maybe not so fast... The battery solution kinda makes sense, I guess, after thinking about it a bit. When the transmitter creates a log, it appends the transmitter time and date to the filename. If the battery isn't powering the internal clock, then maybe the transmitter doesn't know the time and date, and thus cannot create the file. That said, I'm now reserving judgement on the fix pending some additional testing. I went to the field yesterday, and had some other weird things going on. One plane flew without any hitch, but on another, only the throttle would work. Also, the transmitter clock had reset to Dec 31 1999. Gotta do some more investigation. Could be the battery/logging issue is just a symptom of a deeper problem.

[pmullen503]

You RTC should not reset if the battery is good and making good contact in the holder. Even with a dead RTC battery mine never had other issues and judging by the last good log file it had been dead for a couple months.

[JBWingnut]

So my bad on my previous post. Turns out that I am the "deeper problem". The airplane controls issue was due to human stupidity. I neglected to cycle the sticks when I did a receiver stabilizer check on the S6R receiver. I did another check procedure, this time the correct way, and all controls now function normally.

I took the transmitter case apart and checked the RTC battery placement. Maybe, just maybe, the new battery wasn't completely seated under the little retainer strap on the left side of the battery holder. I removed the battery, bent the little contacts out a tiny bit, and replaced the battery making sure it was properly seated. I reset the time and date, and now everything seems back to normal. I'll report back if the problem resurfaces later.

[JBWingnut]

Full week with multiple flying sessions, and all is well. Looks like problem is resolved!