Trouble with telemetry on ESP32C3

[GTorreil]

Hello !

I'm playing with an ESP32C3 and this library. I'm using serial 1 for CRSF. The receiver part worked first-try and i've flown a plane several time with this setup as the receiving end -- it works flawlessly. However, I can't get any telemetry back. I do get the receiver's telemetry (1RSS, 2RSS, and so on) but my calls to telemetryWriteBattery do not seem to send anything back.

Checklist :

• Duplicate ? Not really a duplicate but this may be related to New hardware has arrived! #127 . Although I somehow doubt that since the Rx part works fine. BTW I can totally confirm Rx works on ESP32C3 🥳
• I did "discover" new sensors on the transmitter side (RM Pocket and RM TX16S - same results)
• I tried calling telemetryWriteBattery from loop(), from loop() but with millis()-based timing to limit the rate to 10Hz, and from onReceiveRcChannels
• I read the Telemtry docs
• Edit : I also upgraded Rx and Tx to latest ELRS versions

Repro (or is it ? Maybe i'm just stupid)

Thanks for the feedback on this one !

[ZZ-Cat]

In your gist here, calling Serial1.begin() is the likely culprit.
Serial1.begin() is already internally called in CRSFforArduino::begin(), so calling Serial1.begin() in your sketch is unnecessary. It looks like you have effectively "confused" the firmware by initialising the port with 400K baud and pins 20 and 21 being your Tx and Rx pins, then in the line below it, CRSFforArduino::begin() is initialising Serial1 again with 420K baud and pins 0 and 1 as your Tx and Rx pins.
To verify this, you can go into CFA_Config.hpp, set the DEBUG_ENABLED (I realise I accidentally deleted this flag a while ago in the config. 😅 So, go ahead and add it back in) and CRSF_DEBUG_ENABLE_CONFIGURATION_DUMP flags to 1, build-and-flash your ESP32C3 with these flags enabled, and it will show the actual configuration in the Serial Monitor - the actual configuration may not be what you intend it to be.

All ESP32 targets support custom assignable Serial Tx and Rx pins.
You can pass in your desired pins directly into CFA's constructor, then you can instantiate it with your custom pin settings.
Doing it this way actually tells CFA what pins to use and how to configure them.

10 Hz telemetry updates should be fine. That's what I tested CFA on in the Telemetry Example Sketch.

Calling the telemetryWrite* functions within the context of the onReceiveRcChannels() event has no benefit, because telemetry is actually written out when CRSFforArduino::update() is called.