8000 extmod/modbluetooth: Add gap_indicate_service_changed. · micropython/micropython@fc08bd3 · GitHub
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extmod/modbluetooth: Add gap_indicate_service_changed.
This function triggers an indication on the GATT service changed characteristic.
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‎docs/library/bluetooth.rst

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@@ -746,6 +746,32 @@ Pairing and bonding
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should show the passkey that was provided in the ``_IRQ_PASSKEY_ACTION`` event
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and then respond with either ``0`` (cancel pairing), or ``1`` (accept pairing).
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.. method:: BLE.gap_indicate_service_changed(conn_handle, handle_start, handle_end, /)
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When a client is bonded to a server it will typically cache the results of the discovery
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process to speed up future connections. If the services/characteristic handles change on
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the server in future a previously-bonded client may not be able to communicate correctly
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as it will be using the previously cached handles.
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This function can be run on the server to send an indication to the client that handles
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have changed and trigger service discovery on the client.
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If ``conn_handle`` is None, then all connected devices will be indicated. If CCCD bonding
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is supported then any un-connected bonded devices will automatically be indicated the next
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time they connect.
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The ``handle_start`` and ``handle_end`` arguments can be used to specify the range of
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characteristics that have changed, or typically ``handle_start=0x0000, handle_end=0xFFFF``
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will be used to discover all again.
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Note: with an iOS client it's been seen that if this function is called greater than ~100ms
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after a new connection is established the connection can be dropped, or the characteristics
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covered by the declared range will lock up and be no longer readable, so it's important to
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send this command within the first few ms after a connection is made.
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Alternatively, it appears that if the start and end handles are both set to ``0x0000``,
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the lock-up doesn't occur regardless of when the call is made. Android clients appear to
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accept the null handles as a re-discover all, though the BLE spec makes no mention of this.
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class UUID
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----------

‎extmod/modbluetooth.c

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@@ -709,6 +709,21 @@ STATIC mp_obj_t bluetooth_ble_gap_disconnect(mp_obj_t self_in, mp_obj_t conn_han
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STATIC MP_DEFINE_CONST_FUN_OBJ_2(bluetooth_ble_gap_disconnect_obj, bluetooth_ble_gap_disconnect);
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#if MICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING
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STATIC mp_obj_t bluetooth_indicate_service_changed(size_t n_args, const mp_obj_t *args) {
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(void)n_args;
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int16_t handle = -1;
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if (args[1] != mp_const_none) {
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handle = mp_obj_get_int(args[1]);
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}
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uint16_t hdl_start = mp_obj_get_int(args[2]);
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uint16_t hdl_end = mp_obj_get_int(args[3]);
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mp_bluetooth_indicate_service_changed(handle, hdl_start, hdl_end);
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return mp_const_none;
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}
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STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(bluetooth_indicate_service_changed_obj, 4, 4, bluetooth_indicate_service_changed);
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STATIC mp_obj_t bluetooth_ble_gap_pair(mp_obj_t self_in, mp_obj_t conn_handle_in) {
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(void)self_in;
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uint16_t conn_handle = mp_obj_get_int(conn_handle_in);
@@ -946,6 +961,7 @@ STATIC const mp_rom_map_elem_t bluetooth_ble_locals_dict_table[] = {
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#endif
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{ MP_ROM_QSTR(MP_QSTR_gap_disconnect), MP_ROM_PTR(&bluetooth_ble_gap_disconnect_obj) },
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#if MICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING
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{ MP_ROM_QSTR(MP_QSTR_gap_indicate_service_changed), MP_ROM_PTR(&bluetooth_indicate_service_changed_obj) },
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{ MP_ROM_QSTR(MP_QSTR_gap_pair), MP_ROM_PTR(&bluetooth_ble_gap_pair_obj) },
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{ MP_ROM_QSTR(MP_QSTR_gap_passkey), MP_ROM_PTR(&bluetooth_ble_gap_passkey_obj) },
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#endif

‎extmod/modbluetooth.h

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@@ -355,6 +355,9 @@ int mp_bluetooth_get_preferred_mtu(void);
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int mp_bluetooth_set_preferred_mtu(uint16_t mtu);
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#if MICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING
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// Send an indication on the service changed characteristic, send -1 on conn_handle to indicate to all devices.
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void mp_bluetooth_indicate_service_changed(int16_t conn_handle, uint16_t hdl_start, uint16_t hdl_end);
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// Initiate pairing on the specified connection.
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int mp_bluetooth_gap_pair(uint16_t conn_handle);
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‎extmod/nimble/modbluetooth_nimble.c

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@@ -1082,6 +1082,16 @@ int mp_bluetooth_set_preferred_mtu(uint16_t mtu) {
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}
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#if MICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING
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void mp_bluetooth_indicate_service_changed(int16_t conn_handle, uint16_t hdl_start, uint16_t hdl_end) {
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if (conn_handle == -1) {
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DEBUG_printf("mp_bluetooth_indicate_service_changed all\n");
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return ble_svc_gatt_changed(hdl_start, hdl_end);
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} else {
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DEBUG_printf("mp_bluetooth_indicate_service_changed: conn_handle=%d\n", conn_handle);
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return ble_svc_conn_gatt_changed(conn_handle, hdl_start, hdl_end);
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}
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}
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int mp_bluetooth_gap_pair(uint16_t conn_handle) {
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DEBUG_printf("mp_bluetooth_gap_pair: conn_handle=%d\n", conn_handle);
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return ble_hs_err_to_errno(ble_gap_security_initiate(conn_handle));

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