Feature Request: Configurable CRSF baud rate via CLI

[walll-es]

Feature Request

Problem

Currently the CRSF protocol baud rate is hardcoded to 420000 in the INAV firmware.
There is no way to change it via CLI or GUI.

Some users need to use CRSF at lower baud rates (e.g., 115200) for compatibility
with specific hardware setups or direct connections to radios/other devices
that operate at 115200 baud.

Proposed Solution

Add a CLI parameter to configure CRSF baud rate, for example:

set crsf_baudrate = 115200

This would allow users to select baud rates like 300, 600, 1200, 2400, 4800, 9600, 19200, 38 400, 57600, 115200, 230400. 460800, 921600 or 420000 depending on their needs.

Current Workaround

Currently the only option is to recompile the firmware with modified
CRSF_BAUDRATE define, which is inconvenient and requires technical knowledge.

Additional Context

• Hardware: [ F4V3S Plus Sp Racing F4]
• INAV version: [9.0.1]
• Radio: Radiomaster TX12 with EdgeTX/MPM

Thank you for considering this feature!

[sensei-hacker]

Can you tell me more specifically what you're actually doing here? Connecting the FC to the transmitter is -- not generally how it works.

[walll-es]

Perhaps I'm in the wrong place! I'd like the CRSF protocol baud rate to be configurable, so I don't have to resort to Arduino-style hacks. For example, the TX-12 supports CRSF at 115200, 420000, 921600, and so on. I connected the TX-12 remote control directly to the flight controller via CRSF 420000, and it works perfectly. But unfortunately, 420000 is non-standard in most equipment, making it impossible to use LoRa via network modules or radio modules. I'm forced to either use a hack like an additional board to change the baud rate, or write custom firmware with baud rate control. Okay, if I'm in the wrong place or suggesting something out of the ordinary, I apologize! There are always workarounds.

[sensei-hacker]

Again, can you please tell me what you're trying to accomplish?

Generally, the flight controller is not plugged in to the radio transmitter, so clearly you're trying to do something unusual.

What are you trying to accomplish, please?

making it impossible to use LoRa via network modules

Standard ELRS gear is LORA modules.
mLRS is LORA.
PrivacyLRS is LORA modules.
Most aircraft flying today are flying via LORA modules.
What are you trying to do, please?

I suspect there may be some confusion here between the data rate of the radio link and the bitrate of the UART?

[walll-es]

Yes, in my developments I use non-standard equipment that is usually regulated by standard speeds! Specifically, LoRa E22-***T, E220-***T UART, X-Port network equipment, UART, and RS-485. All I initially proposed was to make CRSF speed more flexible, without strict binding to a specific standard speed. Yes, I would like other protocols to support this, like SBUS, and also to be able to specify not only the speed, but also the presence or absence of a parity bit and the length of the stop bit. Well, I'm getting carried away here and perhaps expecting too much. Okay, if you consider my proposals untenable and of no use to anyone but me, then I apologize for such obscene suggestions!