Model Match forgotten on receiver about expresslrs

[pkendall64]

A transmitter will connect to a receiver when the model number is different (and the RX will do the 3 blink pattern) and you will get telemetry on the radio. The RX will not send any data to the FC or PWM pins in this case.

[pacaj2am]

I know. Yesterday it happened when I:

• disconnected discharged battery (still with 11.V - so receiver was OK)
• connected fresh battery
• I haven't touched any settings on the radio

After connecting the fresh battery radio announced "telemetry recovered" - but I was not able to continue controlling the plane.

When it happened with first RX I thought I might have caused the issue. But now I was sure, that the setting was lost on the RX. I haven't touched the radio/TX while changing the battery. I was alone at the airfield.

[pkendall64]

Did the Lua script script show a model mismatch along the top, and the receiver LED do the 3 blinks to show model match?
Perhaps you should take this to discord in the #help-and-support channel so more people can help you out.

[pacaj2am]

Don't know about LUA. Disabled model match and got output on TX. Later setted up Model Match again - will see how long it will stick.

[mailman451]

I have encountered the same problem on two surface models with two different RadioMaster MT12 (ELRS 3.4.1, EdgeTX 2.10.0), each with it's own binding phrase.

Yesterday on a ER5C-i with ELRS 3.4.0, which I thought was a fluke. Flashed the RX to 3.4.1, configured again and forgot about it. And it happened today on the other MT12 connected to a ER3C-i already at 3.4.1 which then made me look up the issues here.

In both cases, after a power-down of the ESC and when switching on again maybe 30 seconds later, the model match on the RX was reset as was the configuration of the PWM outputs: All outputs back to 50 Hz from 333 Hz and the default failsafe on CH3 back to 988 us instead of my configured 1500 us.

The binding phrase and the WiFi settings were still correct as configured.

The TX Lua script ("Other devices") told me that the model matching on the RX was now "Off", then connecting via WiFi I saw the outputs were reset. When I switched off the model matching on the TX and used "Bind" from the Lua script the receiver connected ("telemetry lost" followed by "telemetry restored") and the model was controllable again.

Configured RX via WiFi and enabled model matching again on the RX and TX, for now it works as it should.

As the RX is inside a closed receiver box I didn't see the RX LED.

[icebalm]

I have seen this multiple times on two of my quads. I think it happens if the receiver goes into binding mode (power on quick three times) but you cancel the bind by just powering off the receiver. The binding UID will stick but the model match data is lost.

[pacaj2am]

this was not happening with 3.3.x

Today it happened again. Lua shows Model Mismatch.

[pacaj2am]

I have seen this multiple times on two of my quads. I think it happens if the receiver goes into binding mode (power on quick three times) but you cancel the bind by just powering off the receiver. The binding UID will stick but the model match data is lost.

It was not in pairing mode.

[pkendall64]

I have been able to reproduce this issue on the bench. It appears to be a power issue causing the config part of the flash (which also contains the power-reset counter) to be reset. This is because as part of the startup we increment the power counter and write to config. The problem is that the ESP erases the flash sector before rewriting it. If the power is removed during that phase (due to a spike etc) then the config is gone and you see the behaviour you are getting.