[Ember Zigbee]Zigbee3.0裝置sleep機制（低功耗）

 針對Simplicity Studio 4，EmberZNet協定棧Zigbee3.0裝置入網流程

Platform：Simplicity Studio 4、EmberZNet SDK 6.4.1.0

【SPP】Content：

Zigbee3.0裝置sleep機制（低功耗）

1、zigbee低功耗裝置進入睡眠需滿足四個條件

1.     emAfForceEndDeviceToStayAwake=FALSE;   才能進入SLEEP
2.     如果emAfStayAwakeWhenNotJoined=1，則隻有裝置加入網絡了才能睡覺
3.     序列槽BUF中要沒有資料才能睡覺
4.     (emberAfGetCurrentSleepControlCallback() != EMBER_AF_STAY_AWAKE)此關系式不成立

bool emAfOkToIdleOrSleep(void)
{
  uint8_t i;

  if (emAfForceEndDeviceToStayAwake) {
    return false;
  }

#if defined(EMBER_AF_PLUGIN_BLE)
  if (emberAfPluginBleHasEventPending()) {
    return false;
  }
#endif

  if (emAfStayAwakeWhenNotJoined) {
    bool awake = false;
    for (i = 0; !awake && i < EMBER_SUPPORTED_NETWORKS; i++) {
      if (emberAfPushNetworkIndex(i) == EMBER_SUCCESS) {
        awake = (emberAfNetworkState() != EMBER_JOINED_NETWORK);
        emberAfPopNetworkIndex();
      }
    }
    if (awake) {
      return false;
    }
  }

#ifdef EM_NUM_SERIAL_PORTS
  for (i = 0; i < EM_NUM_SERIAL_PORTS; i++) {
    if (!emberSerialUnused(i)
        && (emberSerialReadAvailable(i) != 0
            || emberSerialWriteUsed(i) != 0
            || simulatorDoingSerialTx(i))) {
      return false;
    }
  }
#else
  if (!emberSerialUnused(APP_SERIAL)
      && (emberSerialReadAvailable(APP_SERIAL) != 0
          || emberSerialWriteUsed(APP_SERIAL) != 0
          || simulatorDoingSerialTx(APP_SERIAL))) {
    return false;
  }
#endif

  return (emberAfGetCurrentSleepControlCallback() != EMBER_AF_STAY_AWAKE);
}

static EmberAfEventSleepControl defaultSleepControl = EMBER_AF_OK_TO_SLEEP;

EmberAfEventSleepControl emberAfGetCurrentSleepControlCallback(void)
{
  EmberAfEventSleepControl sleepControl = defaultSleepControl;
#ifdef EMBER_AF_GENERATED_EVENT_CONTEXT
  uint8_t i;
  for (i = 0; i < emAfAppEventContextLength; i++) {
    EmberAfEventContext *context = &emAfAppEventContext[i];
    if (emberEventControlGetActive(*context->eventControl)
        && sleepControl < context->sleepControl) {
      sleepControl = context->sleepControl;
    }
  }
#endif
  return sleepControl;
}
           

2、使用者可通過以下協定棧API來控制裝置是否進入休眠

void emberAfForceEndDeviceToStayAwake(bool stayAwake)

// NO PRINTFS.  This may be called in ISR context.
void emberAfForceEndDeviceToStayAwake(bool stayAwake)
{
  emAfForceEndDeviceToStayAwake = stayAwake;
}