mbed-os/features/FEATURE_BLE/ble/services/LinkLossService.h

106 lines
3.4 KiB
C++

/* mbed Microcontroller Library
* Copyright (c) 2006-2013 ARM Limited
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef __BLE_LINK_LOSS_SERVICE_H__
#define __BLE_LINK_LOSS_SERVICE_H__
#include "ble/Gap.h"
/**
* @class LinkLossService
* @brief This service defines behavior when a link is lost between two devices.
* Service: https://developer.bluetooth.org/gatt/services/Pages/ServiceViewer.aspx?u=org.bluetooth.service.link_loss.xml
* Alertness Level Char: https://developer.bluetooth.org/gatt/characteristics/Pages/CharacteristicViewer.aspx?u=org.bluetooth.characteristic.alert_level.xml
*/
class LinkLossService {
public:
enum AlertLevel_t {
NO_ALERT = 0,
MILD_ALERT = 1,
HIGH_ALERT = 2
};
typedef void (* callback_t)(AlertLevel_t level);
/**
* @param bleIn
* BLE object for the underlying controller.
* @param callbackIn Callback invoked upon disconnection.
* @param levelIn Alert level.
*/
LinkLossService(BLE &bleIn, callback_t callbackIn, AlertLevel_t levelIn = NO_ALERT) :
ble(bleIn),
alertLevel(levelIn),
callback(callbackIn),
alertLevelChar(GattCharacteristic::UUID_ALERT_LEVEL_CHAR, reinterpret_cast<uint8_t *>(&alertLevel)) {
static bool serviceAdded = false; /* We should only ever add one LinkLoss service. */
if (serviceAdded) {
return;
}
GattCharacteristic *charTable[] = {&alertLevelChar};
GattService linkLossService(GattService::UUID_LINK_LOSS_SERVICE, charTable, sizeof(charTable) / sizeof(GattCharacteristic *));
ble.gattServer().addService(linkLossService);
serviceAdded = true;
ble.gap().onDisconnection(this, &LinkLossService::onDisconnectionFilter);
ble.gattServer().onDataWritten(this, &LinkLossService::onDataWritten);
}
/**
* Update the callback.
*/
void setCallback(callback_t newCallback) {
callback = newCallback;
}
/**
* Update alertness level.
*/
void setAlertLevel(AlertLevel_t newLevel) {
alertLevel = newLevel;
}
protected:
/**
* This callback allows receiving updates to the AlertLevel characteristic.
*
* @param[in] params
* Information about the characteristic being updated.
*/
virtual void onDataWritten(const GattWriteCallbackParams *params) {
if (params->handle == alertLevelChar.getValueHandle()) {
alertLevel = *reinterpret_cast<const AlertLevel_t *>(params->data);
}
}
void onDisconnectionFilter(const Gap::DisconnectionCallbackParams_t *params) {
if (alertLevel != NO_ALERT) {
callback(alertLevel);
}
}
protected:
BLE &ble;
AlertLevel_t alertLevel;
callback_t callback;
ReadWriteGattCharacteristic<uint8_t> alertLevelChar;
};
#endif /* __BLE_LINK_LOSS_SERVICE_H__ */