ExpressLRS Sudden LQ drop and RX loss at strong RSSI-dBm C++

Excellent, thanks for the post with all the details in one place. This has all the symptoms of a Nonce sync slip, although I do not understand how not only can it happen once (which I never see) but happens over and over. I am going to try to update my long-run testing procedure for roughly the same LQ/RSSI conditions and to watch specifically for this behavior.

1

Answered Sep 27 '21 at 15:11

CapnBry

Here was the test I've run (all on master): * Pair 1: Q X7 with invertermod OpenTX 2.3.14 + SIYI FM30 (no antenna) 10mW 150Hz 1:8 / BetaFPV RX + Betaflight 4.2. Transmitter 10m away with RSSI around -70, LQ 90-100. Quad was "armed", to lock us out if the connection ever failsafes. * Pair 2: FR Mini as TX 10mW 150Hz 1:8 / EP2. Transmitter sitting right next to Pair 1's receiver for maximum interference.

Test was run for 18 hours. No LQ less than 75 was ever experienced (that's where the warning level was set) but I personally never saw anything less than 90 LQ in OpenTX telemetry.

Possible conclusions: * We don't have this issue on master * We don't have this issue on STM32 transmitters paired with ESP receivers * I'm just unlucky

I do not have an ESP32-based Team2.4 TX to test with so I can't think of anything else I can try.

1

Answered Sep 28 '21 at 13:23

CapnBry

If it makes any difference, my TX is always set at 250Hz, TLM 1:32. Advanced telemetry is enabled and 23 sensors are recorded.

Probably not related, but can you flash iNav 3.0 on that FC? We got unlucky twice when iNav 3.0 was in use. ¯_(ツ)_/¯

1

Answered Sep 28 '21 at 13:41

0crap

I wouldn't think the FC would come into play at all, since we're reporting the receiver LQ and I can't think of anything the FC can do to influence our received LQ. You're not running any sort of Lua script for telemetry are you?

1

Answered Sep 28 '21 at 14:05

CapnBry

.... You're not running any sort of Lua script for telemetry are you?

For sure not, banned Yaapu and the like a long time ago. I know the QX7S is very resource limited...

1

Answered Sep 28 '21 at 14:15

0crap

Here was the test I've run (all on master):

• Pair 1: Q X7 with invertermod OpenTX 2.3.14 + SIYI FM30 (no antenna) 10mW 150Hz 1:8 / BetaFPV RX + Betaflight 4.2. Transmitter 10m away with RSSI around -70, LQ 90-100. Quad was "armed", to lock us out if the connection ever failsafes.
• Pair 2: FR Mini as TX 10mW 150Hz 1:8 / EP2. Transmitter sitting right next to Pair 1's receiver for maximum interference.

Test was run for 18 hours. No LQ less than 75 was ever experienced (that's where the warning level was set) but I personally never saw anything less than 90 LQ in OpenTX telemetry.

Possible conclusions:

• We don't have this issue on master
• We don't have this issue on STM32 transmitters paired with ESP receivers
• I'm just unlucky

I do not have an ESP32-based Team2.4 TX to test with so I can't think of anything else I can try.

Are there differences on master vs 1.1.0? I have pretty much same symptoms on r9. I could give a try in master and retest the interference thing.

1

Answered Sep 28 '21 at 17:00

amdnikos