芯科蓝牙BG27开发笔记9-蓝牙温控器例程阅读

源码：

https://download.csdn.net/download/hxkrrzq/88353283

以上源码都是官方资源，可以自行gitbub下载（参见之前笔记）

蓝牙广播格式化

之前的笔记中广播数据是直接使用的十六进制字符串，关于这32bytes数据的格式化在这个例程中，有实例代码。

同时这些例程的readme十分完善。


// Advertising flags (common)
#define ADVERTISE_FLAGS_LENGTH                      2
#define ADVERTISE_FLAGS_TYPE                        0x01

// Bit mask for flags advertising data type
#define ADVERTISE_FLAGS_LE_LIMITED_DISCOVERABLE     0x01
#define ADVERTISE_FLAGS_LE_GENERAL_DISCOVERABLE     0x02
#define ADVERTISE_FLAGS_BR_EDR_NOT_SUPPORTED        0x04

// Scan Response
#define ADVERTISE_MANDATORY_DATA_LENGTH             5
#define ADVERTISE_MANDATORY_DATA_TYPE_MANUFACTURER  0xFF

// Advertise ID
#define ADVERTISE_COMPANY_ID                        0x0047
#define ADVERTISE_FIRMWARE_ID                       0x0000

// Complete local name
#define ADVERTISE_TYPE_LOCAL_NAME                   0x09
#define ADVERTISE_DEVICE_NAME_LEN                   10
#define ADVERTISE_DEVICE_NAME                       "Thermostat"

// Helper macro
#define UINT16_TO_BYTES(x) { (uint8_t)(x), (uint8_t)((x) >> 8) }

// Default advertising scan response parameters
#define ADVERTISE_SCAN_RESPONSE_DEFAULT                                \
  {                                                                    \
    .flags_length = ADVERTISE_FLAGS_LENGTH,                            \
    .flags_type = ADVERTISE_FLAGS_TYPE,                                \
    .flags = ADVERTISE_FLAGS_LE_GENERAL_DISCOVERABLE                   \
             | ADVERTISE_FLAGS_BR_EDR_NOT_SUPPORTED,                   \
    .mandatory_data_length = ADVERTISE_MANDATORY_DATA_LENGTH,          \
    .mandatory_data_type = ADVERTISE_MANDATORY_DATA_TYPE_MANUFACTURER, \
    .company_id = UINT16_TO_BYTES(ADVERTISE_COMPANY_ID),               \
    .firmware_id = UINT16_TO_BYTES(ADVERTISE_FIRMWARE_ID),             \
    .local_name_length = ADVERTISE_DEVICE_NAME_LEN + 1,                \
    .local_name_type = ADVERTISE_TYPE_LOCAL_NAME,                      \
    .local_name = ADVERTISE_DEVICE_NAME                                \
  }

/***************************************************************************//**
 * @brief
 *    Structure that holds Scan Response data
 ******************************************************************************/
typedef struct {
  uint8_t flags_length;          /**< Length of the Flags field. */
  uint8_t flags_type;            /**< Type of the Flags field. */
  uint8_t flags;                 /**< Flags field. */
  uint8_t mandatory_data_length; /**< Length of the mandata field. */
  uint8_t mandatory_data_type;   /**< Type of the mandata field. */
  uint8_t company_id[2];         /**< Company ID. */
  uint8_t firmware_id[2];        /**< Firmware ID */
  uint8_t local_name_length;     /**< Length of the local name field. */
  uint8_t local_name_type;       /**< Type of the local name field. */
  uint8_t local_name[ADVERTISE_DEVICE_NAME_LEN]; /**< Local name field. */
} advertise_scan_response_t;

// The advertising set handle allocated from Bluetooth stack.
static uint8_t advertising_set_handle = 0xff;
static const advertise_scan_response_t adv_scan_response
  = ADVERTISE_SCAN_RESPONSE_DEFAULT;


...
...
...
[设置广播数据]
sc = sl_bt_legacy_advertiser_set_data(advertising_set_handle,
                                            0,        // 类型是广播，而不是广播回包
                                            sizeof(adv_scan_response),
                                            (uint8_t *)&adv_scan_response);

蓝牙事件

void sl_bt_on_event(sl_bt_msg_t *evt)
{
  sl_status_t sc;
  bd_addr address;
  uint8_t address_type;
  uint8_t system_id[8];

  switch (SL_BT_MSG_ID(evt->header)) {
    case sl_bt_evt_system_boot_id:
...
    case sl_bt_evt_connection_opened_id:
...
    case sl_bt_evt_connection_closed_id:
...
    ///
    // Add additional event handlers here as your application requires!      //
    ///

    // -------------------------------
    // Handle configuration characteristics.
    case sl_bt_evt_gatt_server_attribute_value_id:
      break;

    case sl_bt_evt_gatt_server_user_write_request_id:
      thermostat_process_evt_gatt_server_user_write_request(
        &(evt->data.evt_gatt_server_user_write_request));
      break;

    case sl_bt_evt_gatt_server_user_read_request_id:
      thermostat_process_evt_gatt_server_user_read_request(
        &(evt->data.evt_gatt_server_user_read_request));
      break;

    case sl_bt_evt_system_external_signal_id:
      thermostat_process_evt_external_signal(
        evt->data.evt_system_external_signal.extsignals);
      break;

    case sl_bt_evt_system_soft_timer_id:
      break;

    // -------------------------------
    // Default event handler.
    default:
      break;
  }
}

代码中添加了几个蓝牙协议栈的事件，需要搞清楚如何使用：

sl_bt_evt_gatt_server_attribute_value_id

最常见的，手机侧写数据后，会进入此事件，识别写入的value，做出相应动作；

sl_bt_evt_gatt_server_user_write_request_id

简单阅读api.h函数说明后还是不清楚；

参考：

GATT Server and Client Roles，文档中有一段较详细的对比说明：

这个user的意思是，只上报写事件，不直接处理接收到的数据，这个操作粒度比“sl_bt_evt_gatt_server_attribute_value”事件更细。

sl_bt_evt_gatt_server_user_read_request_id

同上

sl_bt_evt_system_soft_timer_id

api文档中：

提示了，此函数超时后会发出此事件。

sl_bt_evt_system_external_signal_id

外部信号是什么？关键的是何时会产生此事件？

同样的搜索api.h和官方帮助文档，都不能获得有效信息，只是说这是外部信号，没找到怎么使用，猜测它是可以自定义的。

继续寻找……

根据api.h文档可以找到“sl_bt_evt_system_external_signal_t”结构体，在接口文档中公开，必然有些地方会使用它。

检索整个蓝牙例程包，发现有多个例程用到了：

具体可以参考例程：bluetooth_ethernet_gateway

最后找到发送信号的函数：

/**
 * @brief Signal the Bluetooth stack that an external event has happened.
 *
 * Signals can be used to report status changes from interrupt context or from
 * other threads to application. Signals are bits that are automatically cleared
 * after application has been notified.
 *
 * If the Platform Core Interrupt API has been configured to use the
 * CORE_ATOMIC_METHOD_BASEPRI as the implementation method of atomic sections,
 * this function must not be called from an interrupt handler with a priority
 * higher than CORE_ATOMIC_BASE_PRIORITY_LEVEL.
 *
 * @param signals is a bitmask defining active signals that are reported back to
 *   the application by system_external_signal-event.
 * @return SL_STATUS_OK if the operation is successful,
 *   SL_STATUS_NO_MORE_RESOURCE indicating the request could not be processed
 *   due to resource limitation at the moment, or SL_STATUS_INVALID_STATE when
 *   the on-demand start feature is used and the stack is currently stopped.
 */
sl_status_t sl_bt_external_signal(uint32_t signals);

反过来，检索sl_bt_external_signal，看看那些地方用到了，怎么使用的。

结果是很多例程使用到了。选“bluetooth_air_quality_monitor”看看：

产生信号的地方：

/***************************************************************************//**
 * Simple Button
 * Button state changed callback
 * @param[in] handle 
 *    Button event handle
 ******************************************************************************/
void sl_button_on_change(const sl_button_t *handle)
{
  // Button released.
  if (sl_button_get_state(handle) == SL_SIMPLE_BUTTON_RELEASED) {
    if (&sl_button_btn0 == handle) {
      sl_bt_external_signal(AIR_QUALITY_MONITOR_BUTTON_EVENT);
    }
  }
}

接收信号：

/***************************************************************************//**
 * Bluetooth stack event handler.
 * This overrides the dummy weak implementation.
 *
 * @param[in] evt Event coming from the Bluetooth stack.
 ******************************************************************************/
void sl_bt_on_event(sl_bt_msg_t *evt)
{
  sl_status_t sc;
  bd_addr address;
  uint8_t address_type;
  uint8_t system_id[8];

  switch (SL_BT_MSG_ID(evt->header)) {
    // -------------------------------
    // This event indicates the device has started and the radio is ready.
    // Do not call any stack command before receiving this boot event!
    case sl_bt_evt_system_boot_id:

.....
      break;

    // -------------------------------
    // This event indicates that a new connection was opened.
    case sl_bt_evt_connection_opened_id:
      connection_opened_handler(evt);
      break;

    // -------------------------------
    // This event indicates that a connection was closed.
    case sl_bt_evt_connection_closed_id:
      connection_closed_handler(evt);
      break;

    // -------------------------------
    // The parameters event
    case sl_bt_evt_connection_parameters_id:
      connection_parameters_handler(evt);
      break;

    // -------------------------------
    // The confirm_bonding event
    case sl_bt_evt_sm_confirm_bonding_id:
      sm_confirm_bonding_handler(evt);
      break;

    // -------------------------------
    // This event triggered after the pairing or bonding procedure is
    // successfully completed.
    case sl_bt_evt_sm_bonded_id:
      app_log("Bluetooth Stack Event : BONDED\r\n");
      break;

    // -------------------------------
    // This event is triggered if the pairing or bonding procedure fails.
    case sl_bt_evt_sm_bonding_failed_id:
      sm_bonding_failed_handler(evt);
      break;

    // Service the gatt server user write request event
    case sl_bt_evt_gatt_server_user_write_request_id:
      // Service write handlers
      air_quality_user_write_callback(evt);
      break;

    // Service the gatt server user read request event
    case sl_bt_evt_gatt_server_user_read_request_id:
      air_quality_user_read_callback(evt);
      break;

    // -------------------------------
    // External signal indication (comes from the interrupt handler)
    case sl_bt_evt_system_external_signal_id:
      air_quality_process_event(evt->data.evt_system_external_signal.extsignals);
    break;

    ///
    // Add additional event handlers here as your application requires!      //
    ///

    // -------------------------------
    // Default event handler.
    default:
      break;
  }
}