Release updates: @lycidias93

ASVD BT Type Helper

What it is and why it exists

ASVD BT Type Helper is a Magisk / priv-app helper for changing Android Bluetooth device type metadata.

It started while I was working on my Audio Safe Volume Disabler / ASVD module. ASVD handles safe-volume / Sound Dose behavior; this helper covers the Bluetooth device-type part I needed during that work.

My Pixel detected a Bluetooth receiver as a headphone-like device. Android Settings showed the device type option, but it was greyed out and not manually changeable. On my reference setup, setting Android Bluetooth metadata key 17 to Carkit made the receiver show up as Car / Auto.

The helper can list paired Bluetooth devices, read metadata key 17, and set it for one explicitly selected device. The main verified use case is Carkit; other metadata values are implemented but still need feedback from other devices and ROMs.

Current status

Area	Status
Current stable release	v0.6.1
Version / versionCode	0.6.1 / 61
Runtime model	Magisk module with privileged helper APK
Package	org.asvd.bttypehelper
Normal APK install	Not supported
Root / Magisk required	Yes
Verified phone	Pixel 10 Pro XL / Android 16 / SDK 36
Verified target	H222 Bluetooth receiver
Verified result	metadata_17=Carkit
Online updates	Enabled via Magisk updateJson
Non-Carkit types	Implemented, experimental until more UI mappings are confirmed
Other phones / OEM ROMs	Unknown, tester feedback needed

Download

All releases:

https://github.com/Lycidias93/asvd-bt-type-helper/releases

Latest release:

https://github.com/Lycidias93/asvd-bt-type-helper/releases/tag/v0.6.1

Download the Magisk ZIP from the newest stable release:

ASVD-BT-Type-Helper-vX.X.X.zip

Do not install this as a normal APK. Flash the ZIP in Magisk.

Install

1. Flash the ZIP in Magisk.
2. Reboot.
3. Grant/check permissions:

tsu /system/bin/sh /data/adb/modules/asvd-bt-type-helper/helper-grant.sh

4. Start the main menu:

tsu /system/bin/sh /data/adb/modules/asvd-bt-type-helper/asvd.sh

Recommended first run

Use the setup wizard first:

tsu /system/bin/sh /data/adb/modules/asvd-bt-type-helper/helper-setup.sh

The wizard lists paired Bluetooth devices, reads the selected target, and asks before writing.

MAC addresses are redacted by default. Use --show-mac only locally when exact MAC targeting is needed. Do not post raw Bluetooth MAC addresses publicly.

Safe flow

1. List or pick the target device.
2. Run dry-run first.
3. Confirm exactly one target match.
4. Apply the wanted type with an explicit confirmation flag.
5. Verify with GET.
6. Run Doctor if something looks wrong.

Dry-run example:

tsu /system/bin/sh /data/adb/modules/asvd-bt-type-helper/helper-set-type.sh --name H222 --type car --dry-run

Expected dry-run markers:

DRY_RUN=yes
write_performed=no
RESULT: ASVD_BT_TYPE_HELPER_SET_TYPE_DRY_RUN_DONE

Apply car / Carkit after a successful dry-run:

tsu /system/bin/sh /data/adb/modules/asvd-bt-type-helper/helper-set-type.sh --name H222 --type car --confirm-set

Verify the target:

tsu /system/bin/sh /data/adb/modules/asvd-bt-type-helper/helper-get.sh --name H222

Expected marker for the verified reference target:

metadata_17_before=Carkit
RESULT: ASVD_BT_TYPE_HELPER_GET_WRAPPER_DONE

Supported type names

CLI type / alias	Metadata value	Status
car, auto, carkit	Carkit	Verified on H222
speaker	Speaker	Experimental
headset, headphones	Headset	Experimental
untethered-headset, earbuds, tws	Untethered Headset	Experimental
watch	Watch	Experimental
stylus, pen	Stylus	Experimental
hearingaid, hearing-aid	HearingAid	Experimental
default	Default	Experimental
clear, reset, null	clear metadata key 17	Implemented, use carefully

Carkit is the verified reference type. Other metadata values are implemented but still need feedback from more devices, ROMs, and OEM Bluetooth settings UIs.

Duplicate-safe picker

Use the duplicate-safe picker when Android shows a custom Bluetooth name, but the backend device name is duplicated.

Example:

• Android UI name: Sauna
• Backend name: Tribit XSound Go
• Two devices have the same backend name

Interactive path:

tsu /system/bin/sh /data/adb/modules/asvd-bt-type-helper/asvd.sh

Then use:

[5] Pick duplicate-safe device
[6] Set picked device dry-run
[7] Set picked device confirmed

Direct helper path:

tsu /system/bin/sh /data/adb/modules/asvd-bt-type-helper/helper-pick-device.sh --filter "Tribit XSound Go"
tsu /system/bin/sh /data/adb/modules/asvd-bt-type-helper/helper-pick-device.sh --filter "Tribit XSound Go" --select 1
tsu /system/bin/sh /data/adb/modules/asvd-bt-type-helper/helper-set-picked.sh --type speaker --dry-run
tsu /system/bin/sh /data/adb/modules/asvd-bt-type-helper/helper-set-picked.sh --type speaker --confirm-set

The picker shows non-secret hints such as candidate_id, source_index, backend_name, metadata_17, duplicate_name, last_connected, dev_type, dev_class, and likely_current_media.

No raw Bluetooth MAC address is shown by default.

Read-only views and reports

Currently connected devices:

tsu /system/bin/sh /data/adb/modules/asvd-bt-type-helper/helper-connected-devices.sh

Last connected Bluetooth hints:

tsu /system/bin/sh /data/adb/modules/asvd-bt-type-helper/helper-last-devices.sh --last-connected

Last devices summary:

tsu /system/bin/sh /data/adb/modules/asvd-bt-type-helper/helper-last-devices.sh

Magisk Action Button report:

/storage/emulated/0/Download/ASVD-BT-Type-Helper-action-latest.txt

The Action Button report is read-only and includes module version, shared ASVD state, Doctor summary, current/last device hints, metadata overview, and recommended commands.

ASVD companion state

The helper writes sanitized shared state for Audio Safe Volume Disabler / ASVD v1.2.6+:

/data/adb/asvd/bt-helper.env

Example fields:

helper_present=1
helper_package=org.asvd.bttypehelper
helper_version=0.6.1
helper_versionCode=61
target_name=H222
requested_type=Carkit
last_result=PASS
current_type=Carkit
previous_type=Carkit
method=metadata_api
asvd_apply_now_triggered=0

The shared-state file must not contain a raw Bluetooth MAC address.

ASVD remains independent. BT Helper is optional and does not force ASVD actions by default.

Optional ASVD apply-now after a confirmed metadata write:

tsu /system/bin/sh /data/adb/modules/asvd-bt-type-helper/helper-set-type.sh --name H222 --type car --confirm-set --asvd-apply-now

Backup, restore and compare

Confirmed SET/CLEAR actions create a backup before writing.

Compare currently paired device types:

tsu /system/bin/sh /data/adb/modules/asvd-bt-type-helper/helper-compare-types.sh

Restore last saved metadata backup:

tsu /system/bin/sh /data/adb/modules/asvd-bt-type-helper/helper-restore-last.sh --dry-run
tsu /system/bin/sh /data/adb/modules/asvd-bt-type-helper/helper-restore-last.sh --confirm-restore

Doctor / health check

tsu /system/bin/sh /data/adb/modules/asvd-bt-type-helper/helper-doctor.sh

Successful result:

RESULT: ASVD_BT_TYPE_HELPER_DOCTOR_PASS

Debug report for GitHub / XDA

Generate a public-safe debug report:

tsu /system/bin/sh /data/adb/modules/asvd-bt-type-helper/helper-debug.sh --name H222

MAC addresses are redacted by default. Do not post output generated with --show-mac publicly.

Reliability notes

v0.6.1

v0.6.1 fixes a Pixel/Termux root-shell broadcast path where am broadcast can fail before the receiver is invoked because system_server is denied access to the Termux PTY (/dev/pts/0).

Changes:

• am broadcast runs detached from the Termux PTY.
• Package preflight output is captured before printing where helper-common.sh is used.
• helper-get.sh uses request_id polling and strict GET result validation.
• helper-get.sh fails if no fresh GET result exists.
• helper-doctor.sh treats GET wrapper failures as real failures.

v0.6.0

v0.6.0 fixes the setup Wizard stale-result failure mode.

Before v0.6.0, the wizard could request LIST but consume an existing last-result.txt from a previous GET, causing a false no_devices_parsed even though Bluetooth access worked.

The wizard now validates result provenance before parsing devices:

action=org.asvd.bttypehelper.LIST
RESULT: ASVD_BT_TYPE_HELPER_LIST_DONE
request_id=<matching request>

Wrong or stale results fail explicitly:

FAIL stale_or_wrong_result action=GET expected=LIST

What this module does not do

• No Google Play Services manipulation.
• No Bluetooth service reload.
• No direct patching of /data/misc/bluedroid/bt_config.conf.
• No background daemon.
• No automatic boot-time Bluetooth metadata changes.
• No automatic ASVD apply-now trigger by default.
• No support for non-root / non-Magisk devices.
• No normal APK install support.

Online updates

The module contains:

updateJson=https://raw.githubusercontent.com/Lycidias93/asvd-bt-type-helper/main/update.json

Magisk uses versionCode for update comparison. v0.6.1 uses versionCode: 61.

Changelog and docs

Full changelog:

• CHANGELOG.md

Additional docs:

• docs/COMPATIBILITY.md
• docs/TESTING.md

Related module:

• Audio Safe Volume Disabler / ASVD: https://github.com/Lycidias93/audio-safe-volume-battery-aware

ASVD BT Type Helper v0.6.4 · Android 17 Root Bridge

v0.6.4 switches the helper from the Android app/priv-app metadata path to a root-side Binder bridge for Android 17.

Why this exists:

• normal user-app metadata GET/SET is blocked by BLUETOOTH_PRIVILEGED on Android 17;
• the systemless priv-app install path was not reliably registered on the tested Android 17 SukiSU/HybridMount setup;
• the root bridge uses IBluetoothManager.registerAdapter(callback) and IBluetooth.getMetadata/setMetadata from root.

Primary helpers:

• helper-get.sh --name <device> reads Bluetooth metadata key 17;
• helper-set-type.sh --name <device> --type <type> writes metadata key 17;
• helper-set-carkit.sh --name <device> sets the type to Carkit;
• helper-doctor.sh checks the root bridge and optional smoke target.

Validated Pixel Android 17 result: H222 changed Carkit -> Speaker -> Carkit and restored cleanly. Logs and repository documentation intentionally avoid raw Bluetooth MAC addresses.