Connection_Parameter.md

Direct-BT Default Connection Parameter

Server

• BTAdapter::setDefaultConnParam():

  • const uint16_t conn_min_interval = 8; // 10ms
  • const uint16_t conn_max_interval = 40; // 50ms
  • const uint16_t conn_latency = 0;
  • const uint16_t supervision_timeout = 50; // 500ms
  • status = adapter->setDefaultConnParam(conn_min_interval, conn_max_interval, conn_latency, supervision_timeout);

• BTAdapter::startAdvertising()

  • static const uint16_t adv_interval_min=160; // x0.625 = 100ms - default is 640 -> 400ms
  • static const uint16_t adv_interval_max=480; // x0.625 = 300ms - default is 640 -> 400ms
  • static const AD_PDU_Type adv_type=AD_PDU_Type::ADV_IND;
  • static const uint8_t adv_chan_map=0x07;
  • static const uint8_t filter_policy=0x00;
  • eir.setConnInterval(8, 12); // 10ms - 15ms

Client

• BTAdapter::startDiscovery():

  • static DiscoveryPolicy discoveryPolicy = DiscoveryPolicy::PAUSE_CONNECTED_UNTIL_READY; // default value
  • static bool le_scan_active = true; // default value
  • static const uint16_t le_scan_interval = 24; // 15ms, default value
  • static const uint16_t le_scan_window = 24; // 15ms, default value
  • static const uint8_t filter_policy = 0; // default value
  • adapter->startDiscovery( discoveryPolicy, le_scan_active, le_scan_interval, le_scan_window, filter_policy );

• BTDevice::connectLE():

  • static const uint16_t le_scan_interval = 24; // 15ms, default value
  • static const uint16_t le_scan_window = 24; // 15ms, default value
  • uint16_t conn_interval_min = (uint16_t)8; // 10ms
  • uint16_t conn_interval_max = (uint16_t)12; // 15ms
  • const uint16_t conn_latency = (uint16_t)0;
  • const uint16_t supervision_timeout = (uint16_t) getHCIConnSupervisorTimeout(conn_latency, (int) ( conn_interval_max * 1.25 ) /* ms */);
  • device->connectLE(le_scan_interval, le_scan_window, conn_interval_min, conn_interval_max, conn_latency, supervision_timeout);