V14 LCD losing memory (RTC)

[Johanl1964]

Is there an existing issue for this problem?

• I have searched the existing issues

What part of EdgeTX is the focus of this bug?

Transmitter firmware

Current Behavior

My V14 sporadically loses its memory for no apparent reason, it’s happened about four times. I measured the RTC battery at 2.98V, so there’s nothing wrong with the battery. Running Nightly b706c40, I had the same problem with the earlier V3.

Expected Behavior

xx

Steps To Reproduce

xx

Version

Nightly (Please give date/commit below)

Transmitter

HelloRadioSky V14LCD

Operating System (OS)

No response

OS Version

No response

Anything else?

xx

[Zimenkov]

Confirm. V14 , after reboot time and date resets to 2000.01.01 00:00

[helloradiosky]

Confirm. V14 , after reboot time and date resets to 2000.01.01 00:00

This issue is likely due to a dead RTC battery; please try replacing it with a CR1220 battery. If that doesn't work, please contact our after-sales support at info@helloradiorc.com

[Johanl1964]

Confirm. V14 , after reboot time and date resets to 2000.01.01 00:00

This issue is likely due to a dead RTC battery; please try replacing it with a CR1220 battery. If that doesn't work, please contact our after-sales support at info@helloradiorc.com

As I wrote, I’ve tested the RTC battery with a multimeter, so there’s nothing wrong with the battery!

[Zimenkov]

Also my CR1220 is 2.96V. It happened after I flashed 2.12 edgetx from official helloradio site.

[Zimenkov]

As I wrote, I’ve tested the RTC battery with a multimeter, so there’s nothing wrong with the battery!

Have you tried come back to 2.10 firmware?

[helloradiosky]

Confirm. V14 , after reboot time and date resets to 2000.01.01 00:00

This issue is likely due to a dead RTC battery; please try replacing it with a CR1220 battery. If that doesn't work, please contact our after-sales support at info@helloradiorc.com

As I wrote, I’ve tested the RTC battery with a multimeter, so there’s nothing wrong with the battery!

In that case, please contact our after-sales team so we can determine whether it is a firmware or hardware issue; once confirmed, they will resolve the matter for you

[helloradiosky]

Thanks for the report — confirmed on V14 / V14LCD.
Cause: On STM32F4, VBAT is ADC1-only. Sampling RTC battery in the MAIN multi-channel DMA scan gives a wrong ~1.0 V reading.
Fix: Sample RTC_BAT alone on ADC1 (EXT), and move MAIN analogs to ADC2 . PR coming shortly.