/* 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_HEART_RATE_SERVICE_H__
#define __BLE_HEART_RATE_SERVICE_H__
#include "BLEDevice.h"
/**
* @class HeartRateService
* @brief BLE Service for HeartRate. This BLE Service contains the location of the sensor, the heartrate in beats per minute.
* Service: https://developer.bluetooth.org/gatt/services/Pages/ServiceViewer.aspx?u=org.bluetooth.service.heart_rate.xml
* HRM Char: https://developer.bluetooth.org/gatt/characteristics/Pages/CharacteristicViewer.aspx?u=org.bluetooth.characteristic.heart_rate_measurement.xml
* Location: https://developer.bluetooth.org/gatt/characteristics/Pages/CharacteristicViewer.aspx?u=org.bluetooth.characteristic.body_sensor_location.xml
*/
class HeartRateService {
public:
/**
* @enum SensorLocation
* @brief Location of HeartRate sensor on body.
*/
enum {
LOCATION_OTHER = 0, /*!< Other Location */
LOCATION_CHEST, /*!< Chest */
LOCATION_WRIST, /*!< Wrist */
LOCATION_FINGER, /*!< Finger */
LOCATION_HAND, /*!< Hand */
LOCATION_EAR_LOBE, /*!< Earlobe */
LOCATION_FOOT, /*!< Foot */
};
public:
/**
* @brief Constructor with 8bit HRM Counter value.
*
* @param[ref] _ble
* Reference to the underlying BLEDevice.
* @param[in] hrmCounter (8-bit)
* initial value for the hrm counter.
* @param[in] location
* Sensor's location.
*/
HeartRateService(BLEDevice &_ble, uint8_t hrmCounter, uint8_t location) :
ble(_ble),
valueBytes(hrmCounter),
hrmRate(GattCharacteristic::UUID_HEART_RATE_MEASUREMENT_CHAR, valueBytes.getPointer(),
valueBytes.getNumValueBytes(), HeartRateValueBytes::MAX_VALUE_BYTES,
GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_NOTIFY),
hrmLocation(GattCharacteristic::UUID_BODY_SENSOR_LOCATION_CHAR, (uint8_t *)&location, sizeof(location), sizeof(location),
GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_READ),
controlPoint(GattCharacteristic::UUID_HEART_RATE_CONTROL_POINT_CHAR, (uint8_t *)&controlPointValue,
sizeof(controlPointValue), sizeof(controlPointValue), GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_WRITE) {
setupService();
}
/**
* @brief Constructor with a 16-bit HRM Counter value.
*
* @param[in] _ble
* Reference to the underlying BLEDevice.
* @param[in] hrmCounter (8-bit)
* initial value for the hrm counter.
* @param[in] location
* Sensor's location.
*/
HeartRateService(BLEDevice &_ble, uint16_t hrmCounter, uint8_t location) :
ble(_ble),
valueBytes(hrmCounter),
hrmRate(GattCharacteristic::UUID_HEART_RATE_MEASUREMENT_CHAR, valueBytes.getPointer(),
valueBytes.getNumValueBytes(), HeartRateValueBytes::MAX_VALUE_BYTES,
GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_NOTIFY),
hrmLocation(GattCharacteristic::UUID_BODY_SENSOR_LOCATION_CHAR, (uint8_t *)&location, sizeof(location), sizeof(location),
GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_READ),
controlPoint(GattCharacteristic::UUID_HEART_RATE_CONTROL_POINT_CHAR, (uint8_t *)&controlPointValue,
sizeof(controlPointValue), sizeof(controlPointValue), GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_WRITE) {
setupService();
}
/**
* @brief Set a new 8-bit value for heart rate.
*
* @param[in] hrmCounter
* HeartRate in bpm.
*/
void updateHeartRate(uint8_t hrmCounter) {
valueBytes.updateHeartRate(hrmCounter);
ble.updateCharacteristicValue(hrmRate.getValueAttribute().getHandle(), valueBytes.getPointer(), valueBytes.getNumValueBytes());
}
/**
* Set a new 16-bit value for heart rate.
*
* @param[in] hrmCounter
* HeartRate in bpm.
*/
void updateHeartRate(uint16_t hrmCounter) {
valueBytes.updateHeartRate(hrmCounter);
ble.updateCharacteristicValue(hrmRate.getValueAttribute().getHandle(), valueBytes.getPointer(), valueBytes.getNumValueBytes());
}
/**
* This callback allows the HeartRateService to receive updates to the
* controlPoint Characteristic.
*
*/
virtual void onDataWritten(const GattCharacteristicWriteCBParams *params) {
if (params->charHandle == controlPoint.getValueAttribute().getHandle()) {
/* Do something here if the new value is 1; else you can override this method by
* extending this class.
* @NOTE: if you are extending this class, be sure to also call
* ble.onDataWritten(this, &ExtendedHRService::onDataWritten); in
* your constructor.
*/
}
}
private:
void setupService(void) {
static bool serviceAdded = false; /* We should only ever need to add the heart rate service once. */
if (serviceAdded) {
return;
}
GattCharacteristic *charTable[] = {&hrmRate, &hrmLocation, &controlPoint};
GattService hrmService(GattService::UUID_HEART_RATE_SERVICE, charTable, sizeof(charTable) / sizeof(GattCharacteristic *));
ble.addService(hrmService);
serviceAdded = true;
ble.onDataWritten(this, &HeartRateService::onDataWritten);
}
private:
/* Private internal representation for the bytes used to work with the vaulue of the heart-rate characteristic. */
struct HeartRateValueBytes {
static const unsigned MAX_VALUE_BYTES = 3; /* FLAGS + up to two bytes for heart-rate */
static const unsigned FLAGS_BYTE_INDEX = 0;
static const unsigned VALUE_FORMAT_BITNUM = 0;
static const uint8_t VALUE_FORMAT_FLAG = (1 << VALUE_FORMAT_BITNUM);
HeartRateValueBytes(uint8_t hrmCounter) : valueBytes() {
updateHeartRate(hrmCounter);
}
HeartRateValueBytes(uint16_t hrmCounter) : valueBytes() {
updateHeartRate(hrmCounter);
}
void updateHeartRate(uint8_t hrmCounter) {
valueBytes[FLAGS_BYTE_INDEX] &= ~VALUE_FORMAT_FLAG;
valueBytes[FLAGS_BYTE_INDEX + 1] = hrmCounter;
}
void updateHeartRate(uint16_t hrmCounter) {
valueBytes[FLAGS_BYTE_INDEX] |= VALUE_FORMAT_FLAG;
valueBytes[FLAGS_BYTE_INDEX + 1] = (uint8_t)(hrmCounter & 0xFF);
valueBytes[FLAGS_BYTE_INDEX + 2] = (uint8_t)(hrmCounter >> 8);
}
uint8_t *getPointer(void) {
return valueBytes;
}
const uint8_t *getPointer(void) const {
return valueBytes;
}
unsigned getNumValueBytes(void) const {
return 1 + ((valueBytes[FLAGS_BYTE_INDEX] & VALUE_FORMAT_FLAG) ? sizeof(uint16_t) : sizeof(uint8_t));
}
private:
/* First byte = 8-bit values, no extra info, Second byte = uint8_t HRM value */
/* See --> https://developer.bluetooth.org/gatt/characteristics/Pages/CharacteristicViewer.aspx?u=org.bluetooth.characteristic.heart_rate_measurement.xml */
uint8_t valueBytes[MAX_VALUE_BYTES];
};
private:
BLEDevice &ble;
HeartRateValueBytes valueBytes;
uint8_t controlPointValue;
GattCharacteristic hrmRate;
GattCharacteristic hrmLocation;
GattCharacteristic controlPoint;
};
#endif /* #ifndef __BLE_HEART_RATE_SERVICE_H__*/