PPM Mode ARM on Ch5: Conflicts with Built-In Mixes in Older Systems (Futaba, Hitec)

[WarhawkCZ]

Current Behavior

ELRS v3.4 added the support for the PPM input. This allows using ELRS Tx modules with older radio systems (Futaba, Hitec, Graupner, etc.). These systems are still very capable, especially for traditional R/C planes. However, many in-built wing mixes, (e.g. butterfly) collide with the channel 5 that is reserved for ARMing. Typically, it is not possible to re-map the mix to a different channel.

Steps to Reproduce

Use any kind of an older radio as the signal source for the ELRS Tx Module.

Possible Solution (Not obligatory)

Change the order of channels such the Ch5 for ARMing is the last one. This one is typically free. Now: CH1, CH2, CH3, CH4, CH5, CH6, CH7, CH8, CH9 New: CH1, CH2, CH3, CH4, CH6, CH7, CH8, CH9, CH5 Alternatively, clarify in the manual if it is safe to permanently operate the system ARMed and provide the solution to enforce so.

Details

Original PPM Pull request: https://github.com/ExpressLRS/ExpressLRS/pull/2528

Your Environment

• TX hardware: Futaba T9CAP with Jumper Aion ELRS 2.4G TX Nano
• RX hardware: any
• ExpressLRS version (TX & RX MUST MATCH): v3.4 FCC

Many thanks to all of you for consideration and your hard work.

[stanislavdavid]

It can by solved by PR #2801 or #2869

[WarhawkCZ]

It can by solved by PR #2801 or #2869

This is excellent reply @stanislavdavid . I actually like the Limits feature as well as the radio misses it. It would be great adding these PRs.