[pfeerick]

Fork PR for CI firmware builds and bench testing. Not for upstream yet.

Trainer lead option

Some radios put trainer input and output on different 3.5mm jack contacts and ship with a crossover lead. On PL18U, EL18 and PA01, input is on the tip and output on the ring. ST16 was defined the other way round; this PR swaps its pins to match (see below). With a mono lead, as used by most other radios, the ring is grounded, so whichever direction is on the ring stops working. Pulling the plug partly out works around it.

This adds a Trainer lead option to Radio Setup → Hardware on boards that set trainer_jack_crossover in their hw_defs:

• Crossover (default): existing behaviour.
• Standard: input and output both on the tip, for mono or straight leads.

Flagged boards: PL18, PL18EV, PL18U, NB4P, NV14, EL18, PA01 and ST16. On all of them input is on the tip, so Standard simply sends on the input pin as well. Of these, only PL18U, EL18, PA01 and ST16 have been tested so far, and only on firmware without this change. The others use the same pins as PL18U and EL18.

The setting takes a spare bit in the colour-screen radio settings, so the settings struct doesn't grow. It's added to the YAML for all colour targets but only used on flagged boards. Changing it restarts the trainer on the new contacts straight away.

Alternative to EdgeTX#6970, which moves PL18-family output to the tip unconditionally and would break pairing over the supplied crossover lead.

Companion

Companion reads and writes trainerTipOnly and shows the same Crossover / Standard choice on its Hardware page for flagged boards, so saving radio settings from Companion keeps the setting.

ST16 pin swap

ST16 had trainer in on PE5 (ring) and out on PE6 (tip), so it couldn't pair with the other Flysky radios over the crossover lead. The schematic's MCU sheet names PE5 PPM_IN and PE6 PPM_OUT, but the jack sheet labels the PE6 path PPM_INPUT and the PE5 path PPM_OUTPUT. Each path is only a 200R resistor plus ESD clamps, so this follows the jack sheet: in on PE6 (tip), out on PE5 (ring). This is a behaviour change for ST16: on the default Crossover setting it now pairs with PL18U/EL18/PA01 over the supplied lead, and slave over a mono lead needs Standard.

Also included

fix(bw): TR_JACK_MODES was built from the country-code strings, so the Jack mode option on X-Lite S and X-Lite Pro showed US/JP/EU instead of Ask/Audio/Trainer.

Test plan

• PL18U, EL18, PA01, ST16 with a Pocket over a mono lead, set to Standard: master and slave both work with the plug fully in.
• Same radios set to Crossover: pairing over the supplied crossover lead still works.
• Switching the option while the trainer is running takes effect without a reboot.

Known gaps

• The new strings are English in all languages.

🤖 Generated with Claude Code