Do not allow the user to switch radios while pressing the PTT

[Wetmelon]

The current behaviour of SRS is as follows:

• User presses PTT
  • SRS Broadcasts on radio 1
• User presses radio 2
  • SRS stops broadcasting on radio 1
  • SRS switches to radio 2
  • SRS starts broadcasting on radio 2

This is generally ok, but it becomes less ideal when radio 1 and 2 only differ by a modifier. I discovered that with the following settings:

And "Radio switch works as PTT" setting, it becomes very easy to accidentally broadcast on the wrong radio when stopping a transmission. I find that I press the modifier first then the broadcast button reliably but it's very easy to sequence them the wrong way when ending the transmission, so sometimes I let go of the modifer which immediately switches me to radio 1 and starts broadcasting.

I propose that switching radios should not be allowed while PTT is depressed. This means the above example would look like:

• User presses PTT
  • SRS broadcasts on radio 1
• User presses Radio 2
  • SRS ignores input
• User releases PTT
  • SRS stops broadcasting on radio 1
• User presses radio 2
  • SRS switches to radio 2
• User presses PTT
  • SRS starts broadcasting on radio 2

This should work the same way if "Radio switch as PTT" is selected:

• User presses radio 1
  • SRS switches to radio 1 and broadcasts on radio 1
• User presses radio 2
  • SRS ignores input
• User releases radio 1
  • SRS stops broadcasting on radio 1
  • Note that SRS does NOT start broadcasting on radio 2 immediately
• User releases radio 2
  • SRS does nothing
• User presses radio 2
  • SRS switches to radio 2 and broadcasts on radio 2

Essentially, this is just an edge-triggered state machine with "switch radio" states that cannot be reached while broadcasting. This should take care of itself in the case of multi-radio broadcasting, as all radios which were selected when broadcasting started will stay selected until broadcasting ends.

[syn111]

This is not how real PTT behaves

[justin-lovell]

@syn111, I agree. However, SRS does not do concurrent transmissions over other radios when more than one PTT is used. In the real world, the buttons are gate-guarded or both radios would transmit concurrently.

The PR mentioning this issue would implement the logic as proposed by @Wetmelon.

However, it should be noted that the modifier on the same PTT key needs further work.