低功耗蓝牙里重要的三个连接参数：Connection Interval,Slave Latency,Supervision Timeout.这三个参数决定了BLE的功耗。

    更新连接参数的相关api： 

/********************************************************************
 * @fn          GAPRole_SendUpdateParam
 *
 * @brief       Update the parameters of an existing connection
 *
 * @param       minConnInterval - the new min connection interval
 * @param       maxConnInterval - the new max connection interval
 * @param       latency - the new slave latency
 * @param       connTimeout - the new timeout value
 * @param       handleFailure - what to do if the update does not occur.
 *              Method may choose to terminate connection, try again, or take no action
 *
 * @return      SUCCESS, bleNotConnected, or bleInvalidRange
 */
bStatus_t GAPRole_SendUpdateParam( uint16 minConnInterval, uint16 maxConnInterval,
                                   uint16 latency, uint16 connTimeout, uint8 handleFailure )

    ● Interval Max * (Slave Latency + 1) ≤ 2 seconds
    ● Interval Min ≥ 20 ms
    ● Interval Min + 20 ms ≤ Interval Max Slave Latency ≤ 4
    ● connSupervisionTimeout ≤ 6 seconds
    ● Interval Max * (Slave Latency + 1) * 3 < connSupervisionTimeout

BLE固件开发--更新连接参数