This example implements the Telephony and Media Audio Profile (TMAP) Broadcast Media Sender (BMS) role. The device acts as a non-connectable BAP Broadcast Source: extended advertising carries the TMAS service UUID with the BMS role flag, the Broadcast Audio Announcement service with a 24-bit broadcast ID (0x123456), and the complete local name ("TMAP Broadcast Source"); periodic advertising carries the encoded BASE.

The implementation uses the ESP-BLE-AUDIO library for the TMAP role registration and the CAP initiator broadcast pieces. A single subgroup with one stream is configured from the LC3 48_2_1 broadcast preset (front-left location, media context). After the broadcast source is created and the BIG is started, a periodic TX scheduler (example_audio_tx_scheduler_*) drives ISO SDU transmission at the stream's QoS interval, and a sent callback tracks packet counts and drift.

Requirements

A board with BLE 5.2, ISO, and LE Audio support (e.g. ESP32-H4, ESP32-S31)
Peer device running the paired example

Configuration

idf.py menuconfig

No build-time options — runtime defaults are baked into source.

Security & Pairing

Security is inherited from ../../common_components/example_init/ble_audio_example_init.c: LE Secure Connections with bonding enabled, no MITM, Just-Works pairing (BLE_SM_IO_CAP_NO_IO). The BMS broadcast itself is non-connectable and unencrypted, so these settings only apply if a peer ever opens an ATT connection.

Build & Flash

The base sdkconfig.defaults defaults to the Bluedroid host; idf.py automatically merges the per-target overlay (sdkconfig.defaults.$IDF_TARGET). To build with NimBLE host instead, layer sdkconfig.defaults.nimble on top via -DSDKCONFIG_DEFAULTS.

Bluedroid host (default)

idf.py set-target esp32h4
idf.py -p PORT flash monitor

NimBLE host

idf.py set-target esp32h4
idf.py -DSDKCONFIG_DEFAULTS="sdkconfig.defaults;sdkconfig.defaults.esp32h4;sdkconfig.defaults.nimble" -p PORT flash monitor

For esp32s31, replace the chip overlay accordingly.

(Exit serial monitor with Ctrl-].)

Example Flow

Initialize NVS, the Bluetooth controller/host, and the LE Audio common layer (no GAP/GATT app callbacks).
Register the TMAP role as ESP_BLE_AUDIO_TMAP_ROLE_BMS and initialize the CAP initiator (register stream ops, init TX scheduler).
Start the audio stack, then build the create params (1 subgroup × 1 stream, LC3 48_2_1 preset, sequential packing, no encryption) and create the broadcast source.
Configure and start non-connectable extended advertising (TMAS+BMS role, Broadcast Audio + broadcast ID 0x123456, device name) and periodic advertising carrying the BASE.
Add the advertising handle to the BIG and start broadcast audio; on stream-started, allocate the SDU buffer and arm the TX scheduler at qos->interval.
The scheduler callback fills SDUs with the rolling sequence number and calls esp_ble_audio_cap_stream_send; the sent callback updates RX-side metrics via example_audio_tx_scheduler_on_sent.
cap_initiator_update and cap_initiator_stop are exposed for runtime metadata refresh and teardown.

Expected Log

TAG is TMAP_BMS.

Init:

I (xxx) TMAP_BMS: CAP initiator initialized

Setup:

I (xxx) TMAP_BMS: Creating broadcast source
I (xxx) TMAP_BMS: Advertising started (handle 0)
I (xxx) TMAP_BMS: CAP initiator setup

Streaming:

I (xxx) TMAP_BMS: [SRC #0] Stream started

(Subsequent per-packet metrics are emitted by example_audio_tx_scheduler_on_sent under the SRC #0 label.)

Stop / teardown:

I (xxx) TMAP_BMS: [SRC #0] Stream stopped, reason 0x..
I (xxx) TMAP_BMS: [SRC #0] ISO disconnected, reason 0x..
I (xxx) TMAP_BMS: Advertising stopped (handle 0)

Errors (representative):

E (xxx) TMAP_BMS: Failed to create broadcast source, err ..
E (xxx) TMAP_BMS: Failed to start broadcast source, err ..
E (xxx) TMAP_BMS: [SRC #0] Invalid stream qos
E (xxx) TMAP_BMS: [SRC #0] Failed to alloc TX buffer, SDU ..

Peer Pairing

Run bmr on a second board.

Flash and boot the BMR peer; it starts scanning for TMAP BMS advertisers.
Boot this BMS; it advertises with TMAS BMS role and broadcast ID 0x123456 and starts periodic advertising carrying the BASE.
The BMR matches the TMAS BMS role plus Broadcast Audio UUID, creates a PA sync, and waits for the BASE.
After BASE is received the BMR creates a broadcast sink and syncs to the BIG using the BIS index bitfield.
The BMS stream-started callback fires; its TX scheduler begins emitting SDUs that the BMR receives in its stream recv callback.
Stopping or power-cycling the BMS triggers PA sync loss on the BMR, which deletes the sink and resumes scanning.

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TMAP Broadcast Media Sender (BMS) Example

Overview