低功耗蓝牙4.0BLE编程-nrf51822开发(2)
相关下载：http://download.csdn.net/detail/xgbing/9565708
首先看的示例是心率计一个示例程序：
打开工程前需要下载蓝牙协议栈S110 nRF51822 SoftDevice（s110_nrf51822_6.0.0_softdevice.hex）到板子中，这个手册上有说明。
首先看的是main.c中的main函数：
/*****************************************************************************
* Main Function
*****************************************************************************/
/**@brief Function for the application main entry.
*/
int main(void)
{
uint32_t err_code;
timers_init();
gpiote_init();
buttons_init();
ble_stack_init();
bond_manager_init();
// Initialize Bluetooth Stack parameters
gap_params_init();
advertising_init();
services_init();
conn_params_init();
sec_params_init();
// Start advertising
advertising_start();
// Enter main loop
for (;;)
{
// Switch to a low power state until an event is available for the application
err_code = sd_app_evt_wait();
APP_ERROR_CHECK(err_code);
}
}
它很简洁：初始化->start->loop。
(1)Timer初始化
/**@brief Function for the Timer initialization.
*
* @details Initializes the timer module. This creates and starts application timers.
*/
static void timers_init(void)
{
uint32_t err_code;
// Initialize timer module
APP_TIMER_INIT(APP_TIMER_PRESCALER, APP_TIMER_MAX_TIMERS, APP_TIMER_OP_QUEUE_SIZE, false);
// Create timers
err_code = app_timer_create(&m_battery_timer_id,
APP_TIMER_MODE_REPEATED,
battery_level_meas_timeout_handler);
APP_ERROR_CHECK(err_code);
err_code = app_timer_create(&m_heart_rate_timer_id,
APP_TIMER_MODE_REPEATED,
heart_rate_meas_timeout_handler);
APP_ERROR_CHECK(err_code);
}使用app_timer_create创建了两个时钟，处理函数分别是battery_level_meas_timeout_handler和heart_rate_meas_timeout_handler。
/**@brief Function for handling the Battery measurement timer timeout.
*
* @details This function will be called each time the battery level measurement timer expires.
* This function will start the ADC.
*
* @param[in] p_context Pointer used for passing some arbitrary information (context) from the
* app_start_timer() call to the timeout handler.
*/
static void battery_level_meas_timeout_handler(void * p_context)
{
UNUSED_PARAMETER(p_context);
battery_start();
}
/**@brief Function for handling the Heart rate measurement timer timeout.
*
* @details This function will be called each time the heart rate measurement timer expires.
* It will exclude RR Interval data from every third measurement.
*
* @param[in] p_context Pointer used for passing some arbitrary information (context) from the
* app_start_timer() call to the timeout handler.
*/
static void heart_rate_meas_timeout_handler(void * p_context)
{
uint32_t err_code;
UNUSED_PARAMETER(p_context);
err_code = ble_hrs_heart_rate_measurement_send(&m_hrs, m_cur_heart_rate);
if (
(err_code != NRF_SUCCESS)
&&
(err_code != NRF_ERROR_INVALID_STATE)
&&
(err_code != BLE_ERROR_NO_TX_BUFFERS)
&&
(err_code != BLE_ERROR_GATTS_SYS_ATTR_MISSING)
)
{
APP_ERROR_HANDLER(err_code);
}
}时钟创建后并不会自动运行，当调用application_timers_start后时钟开始运行：
/**@brief Function for starting the application timers.
*/
static void application_timers_start(void)
{
uint32_t err_code;
// Start application timers
err_code = app_timer_start(m_battery_timer_id, BATTERY_LEVEL_MEAS_INTERVAL, NULL);
APP_ERROR_CHECK(err_code);
err_code = app_timer_start(m_heart_rate_timer_id, HEART_RATE_MEAS_INTERVAL, NULL);
APP_ERROR_CHECK(err_code);
}
services_init()初始化程序中的三个服务：ble_dis.c, ble_bas.c, ble_hrs.c。
/**@brief Function for initializing the services that will be used by the application.
*
* @details Initialize the Heart Rate, Battery and Device Information services.
*/
static void services_init(void)
{
uint32_t err_code;
ble_hrs_init_t hrs_init;
ble_bas_init_t bas_init;
ble_dis_init_t dis_init;
uint8_t body_sensor_location;
// Initialize Heart Rate Service
body_sensor_location = BLE_HRS_BODY_SENSOR_LOCATION_FINGER;
memset(&hrs_init, 0, sizeof(hrs_init));
hrs_init.is_sensor_contact_supported = false;
hrs_init.p_body_sensor_location = &body_sensor_location;
// Here the sec level for the Heart Rate Service can be changed/increased.
BLE_GAP_CONN_SEC_MODE_SET_OPEN(&hrs_init.hrs_hrm_attr_md.cccd_write_perm);
BLE_GAP_CONN_SEC_MODE_SET_NO_ACCESS(&hrs_init.hrs_hrm_attr_md.read_perm);
BLE_GAP_CONN_SEC_MODE_SET_NO_ACCESS(&hrs_init.hrs_hrm_attr_md.write_perm);
BLE_GAP_CONN_SEC_MODE_SET_OPEN(&hrs_init.hrs_bsl_attr_md.read_perm);
BLE_GAP_CONN_SEC_MODE_SET_NO_ACCESS(&hrs_init.hrs_bsl_attr_md.write_perm);
err_code = ble_hrs_init(&m_hrs, &hrs_init);
APP_ERROR_CHECK(err_code);
// Initialize Battery Service
memset(&bas_init, 0, sizeof(bas_init));
// Here the sec level for the Battery Service can be changed/increased.
BLE_GAP_CONN_SEC_MODE_SET_OPEN(&bas_init.battery_level_char_attr_md.cccd_write_perm);
BLE_GAP_CONN_SEC_MODE_SET_OPEN(&bas_init.battery_level_char_attr_md.read_perm);
BLE_GAP_CONN_SEC_MODE_SET_NO_ACCESS(&bas_init.battery_level_char_attr_md.write_perm);
BLE_GAP_CONN_SEC_MODE_SET_OPEN(&bas_init.battery_level_report_read_perm);
bas_init.evt_handler = NULL;
bas_init.support_notification = true;
bas_init.p_report_ref = NULL;
bas_init.initial_batt_level = 100;
err_code = ble_bas_init(&bas, &bas_init);
APP_ERROR_CHECK(err_code);
// Initialize Device Information Service
memset(&dis_init, 0, sizeof(dis_init));
ble_srv_ascii_to_utf8(&dis_init.manufact_name_str, MANUFACTURER_NAME);
BLE_GAP_CONN_SEC_MODE_SET_OPEN(&dis_init.dis_attr_md.read_perm);
BLE_GAP_CONN_SEC_MODE_SET_NO_ACCESS(&dis_init.dis_attr_md.write_perm);
err_code = ble_dis_init(&dis_init);
APP_ERROR_CHECK(err_code);
}static ble_hrs_t的结构定义：
/**@brief Heart Rate Service structure. This contains various status information for the service. */
typedef struct ble_hrs_s
{
ble_hrs_evt_handler_t evt_handler; /**< Event handler to be called for handling events in the Heart Rate Service. */
bool is_expended_energy_supported; /**< TRUE if Expended Energy measurement is supported. */
bool is_sensor_contact_supported; /**< TRUE if sensor contact detection is supported. */
uint16_t service_handle; /**< Handle of Heart Rate Service (as provided by the BLE stack). */
ble_gatts_char_handles_t hrm_handles; /**< Handles related to the Heart Rate Measurement characteristic. */
ble_gatts_char_handles_t bsl_handles; /**< Handles related to the Body Sensor Location characteristic. */
ble_gatts_char_handles_t hrcp_handles; /**< Handles related to the Heart Rate Control Point characteristic. */
uint16_t conn_handle; /**< Handle of the current connection (as provided by the BLE stack, is BLE_CONN_HANDLE_INVALID if not in a connection). */
bool is_sensor_contact_detected; /**< TRUE if sensor contact has been detected. */
uint16_t rr_interval[BLE_HRS_MAX_BUFFERED_RR_INTERVALS]; /**< Set of RR Interval measurements since the last Heart Rate Measurement transmission. */
uint16_t rr_interval_count; /**< Number of RR Interval measurements since the last Heart Rate Measurement transmission. */
} ble_hrs_t;ble_hrs.h/ble_hrs.c是心率计程序服务的代码。
buttons_init(void)初始化两个按钮：HR_INC_BUTTON_PIN_NO和HR_DEC_BUTTON_PIN_NO，分别模拟心率计的加减。
/**@brief Function for initializing the button module.
*/
static void buttons_init(void)
{
// Configure HR_INC_BUTTON_PIN_NO and HR_DEC_BUTTON_PIN_NO as wake up buttons and also configure
// for 'pull up' because the eval board does not have external pull up resistors connected to
// the buttons.
static app_button_cfg_t buttons[] =
{
{HR_INC_BUTTON_PIN_NO, false, BUTTON_PULL, button_event_handler},
{HR_DEC_BUTTON_PIN_NO, false, BUTTON_PULL, button_event_handler} // Note: This pin is also BONDMNGR_DELETE_BUTTON_PIN_NO
};
APP_BUTTON_INIT(buttons, sizeof(buttons) / sizeof(buttons[0]), BUTTON_DETECTION_DELAY, false);
}当按下按钮时，处理程序是button_event_handler()，它处理心率计的加减模拟：
/**@brief Function for handling button events.
*
* @param[in] pin_no The pin number of the button pressed.
*/
static void button_event_handler(uint8_t pin_no, uint8_t button_action)
{
if (button_action == APP_BUTTON_PUSH)
{
switch (pin_no)
{
case HR_INC_BUTTON_PIN_NO:
// Increase Heart Rate measurement
m_cur_heart_rate += HEART_RATE_CHANGE;
if (m_cur_heart_rate > MAX_HEART_RATE)
{
m_cur_heart_rate = MIN_HEART_RATE; // Loop back
}
break;
case HR_DEC_BUTTON_PIN_NO:
// Decrease Heart Rate measurement
m_cur_heart_rate -= HEART_RATE_CHANGE;
if (m_cur_heart_rate < MIN_HEART_RATE)
{
m_cur_heart_rate = MAX_HEART_RATE; // Loop back
}
break;
default:
APP_ERROR_HANDLER(pin_no);
break;
}
}
}