Bug with Sram etap 11s after firmware upgrade to 21.17

After firmware upgrade, there are several errors in the 840 - Sram etap 11s communication:

- incorrect reading of the gearings, continuosly alternating e.g. 50 - 34

- annoying beep every about 10 seconds

- the rear derailleaur stop to work (!). I cannot confirm it is because of the upgrade, but it happened two times, the second one after deleting the sensor and repeating the pairing.

I had to disable the sensor, otherwise it is impossible to ride with the continuous beeps of the Edge

Is it possible to downgrade the firmware?

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0 Ken-L 5 months ago

I have the same issues on my Edge 540 both with 21.17 and 21.18.

Sram eTap 11 -- the unit connects and disconnects continuously alternative between showing the correct gearing 2x11 and "ghost" gearing of 4x15. The continuous beeping makes me want to yeet the unit into the weeds!

0 aweatherall 5 months ago in reply to Ken-L

I think what would needed would be logs of the ANT radio traffic. Let me know if you would be willing to enable logging and share those logs.

0 Ken-L 5 months ago in reply to aweatherall

Sure thing! I can run a test tomorrow if you let me know how to enable logging (and where the logs are kept).

0 aweatherall 5 months ago in reply to Ken-L

@Ken-L sent you a private message

0 stepolin 5 months ago in reply to aweatherall

If you want logs also from the 840, let me know how to do

0 aweatherall 4 months ago in reply to stepolin

Ken-L Thanks for the data.

0 aljado 4 months ago

I have this issue too, showing on my 840 and my Forerunner 965. I sent one RD back because I thought the fault lay there but the replacement is just the same. I have RED-RD-E-A2 and it only occurs on this. Works fine on an A1 RD I have, as well as several AXS RDs. Video attached

0 Ken-L 4 months ago in reply to aljado

Interesting re: the A2 vs A1 derailleur. I'm also on a RED-RD-E-A2 derailleur and had a thought a few days ago of trying to completely re-pair it (shifters, FD, and 540 headunit).

@aweatherall did the ANT traffic logs uncover anything? (appreciate you taking a look)

0 aweatherall 4 months ago in reply to Ken-L

It definitely shows a problem and I have passed the data on to both Garmin and SRAM. When I hear something back I will let you know.

0 aweatherall 4 months ago in reply to aweatherall

The problem will need a fix from SRAM.

It is not correctly handling message requests that it does not support. The ANT+ specification defines how unsupported messages/requests should be handled. It is currently not doing that correctly.

I'm guessing that is due to the new message types that were added for button support.