Bluetooth headset microphone not recognized / Missing "Bluetooth Headset Mode" activation

[matrixpsk]

Describe the bug

FT8AF does not automatically enable Android's "Bluetooth Headset Mode" when a Bluetooth headset is connected. As a result, the app does not recognize the headset's microphone or speaker as available audio devices, making it impossible to use FT8AF with a Bluetooth headset.

Expected behavior

When a Bluetooth headset is connected and FT8AF is launched, the app should trigger Android's built-in BluetoothHeadset mode (similar to what FT8CN does). This would allow the app to capture audio from the headset's microphone and play audio to its earpiece/speaker.

Actual behavior

• FT8AF does not request or enable Bluetooth Headset Mode.

• The Bluetooth headset does not appear in the list of available audio input/output devices within the app.

• No audio is captured from or played to the Bluetooth headset.

Workaround (confirms the issue)

1. Launch FT8CN first (it triggers the system message: "Enter bluetooth headset mode" and shows a microphone icon in the Android status bar).

2. Minimize FT8CN (keep it running in the background).

3. Launch FT8AF – now the Bluetooth headset appears as an available audio device and audio works correctly.

4. If FT8CN is closed, the system exits Bluetooth Headset Mode, and FT8AF immediately loses access to the Bluetooth audio device again.

Environment

App: FT8AF 0.149 dev.677

Android version: 16, 13

Device: Vivo X200 Pro, Samsung SM-T325

Bluetooth headset: KCX_BT003_V1.1, BT5.0-Audio-PRO

Possible cause

FT8AF appears to lack the necessary system call to enable BluetoothHeadset mode on startup. FT8CN includes this logic, which is why the workaround succeeds.

Suggested fix

Implement the same Bluetooth headset activation routine used in FT8CN, likely involving:

• BluetoothAdapter

• BluetoothHeadset

• AudioManager with setBluetoothScoOn() and startBluetoothSco()

This would make FT8AF behave identically to FT8CN in terms of Bluetooth audio support and remove the dependency on having FT8CN running in the background.

Additional context

This is a regression or omission in the fork, as the original FT8CN handles this correctly. Adding this feature would greatly improve usability for field operations where Bluetooth headsets are commonly used.

[patrickrb]

Taking a look at this today

[patrickrb]

Confirmed — and your analysis was spot on

FT8AF was only starting Android's Bluetooth SCO (headset) mode when the rig connection mode itself was Bluetooth. If you were on a USB or VOX rig and just selected a Bluetooth headset as the audio device, the app never called startBluetoothSco(), so it captured the built-in mic instead and the headset didn't work — which is why launching FT8CN first (it turns SCO on unconditionally) made the device appear.

The reason it wasn't unconditional is deliberate: forcing SCO on knocks any paired car/headphones out of A2DP music, so it had been restricted to Bluetooth-rig mode after an earlier "car stereo keeps pausing" bug. The missing piece was that choosing a BT headset as the FT8 mic/speaker is itself explicit consent to route over it.

Fix (PR #776, targets dev)

• Selecting a Bluetooth-SCO input or output device in Settings now enters headset mode and rebuilds the audio capture so the mic actually routes over the headset — on any rig type (USB / VOX / BT).
• Still gated so it only fires when a BT audio profile is actually connected, and it never disturbs SCO for a Bluetooth rig — so the car-music case stays protected.
• Applied at launch too, so a remembered BT-headset selection comes up in headset mode automatically without needing FT8CN in the background.

This is complementary to PR #772 (issue #759), which hardens how the SCO link is brought up and retried — this PR fixes when it's started.

Thanks for the detailed write-up and the FT8CN comparison, @matrixpsk — it made the gap obvious.

[patrickrb]

This fix is in testing on: https://github.com/patrickrb/FT8AF/releases/tag/android-dev.1137