Diff: features/FEATURE_BLE/ble/services/HeartRateService.h

Revision:

0:6c56fb4bc5f0

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/features/FEATURE_BLE/ble/services/HeartRateService.h	Fri Nov 04 20:27:58 2016 +0000
@@ -0,0 +1,194 @@
+/* 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 "ble/BLE.h"
+
+/**
+* @class HeartRateService
+* @brief BLE Service for HeartRate. This BLE Service contains the location of the sensor and the heart rate 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 the heart rate 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 8-bit HRM Counter value.
+     *
+     * @param[ref] _ble
+     *               Reference to the underlying BLE.
+     * @param[in] hrmCounter (8-bit)
+     *               Initial value for the HRM counter.
+     * @param[in] location
+     *               Sensor's location.
+     */
+    HeartRateService(BLE &_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_READ | GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_NOTIFY),
+        hrmLocation(GattCharacteristic::UUID_BODY_SENSOR_LOCATION_CHAR, &location),
+        controlPoint(GattCharacteristic::UUID_HEART_RATE_CONTROL_POINT_CHAR, &controlPointValue) {
+        setupService();
+    }
+
+    /**
+     * @brief Constructor with a 16-bit HRM Counter value.
+     *
+     * @param[in] _ble
+     *               Reference to the underlying BLE.
+     * @param[in] hrmCounter (8-bit)
+     *               Initial value for the HRM counter.
+     * @param[in] location
+     *               Sensor's location.
+     */
+    HeartRateService(BLE &_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, &location),
+        controlPoint(GattCharacteristic::UUID_HEART_RATE_CONTROL_POINT_CHAR, &controlPointValue) {
+        setupService();
+    }
+
+    /**
+     * @brief Set a new 8-bit value for the heart rate.
+     *
+     * @param[in] hrmCounter
+     *                  Heart rate in BPM.
+     */
+    void updateHeartRate(uint8_t hrmCounter) {
+        valueBytes.updateHeartRate(hrmCounter);
+        ble.gattServer().write(hrmRate.getValueHandle(), valueBytes.getPointer(), valueBytes.getNumValueBytes());
+    }
+
+    /**
+     * Set a new 16-bit value for the heart rate.
+     *
+     * @param[in] hrmCounter
+     *                  Heart rate in BPM.
+     */
+    void updateHeartRate(uint16_t hrmCounter) {
+        valueBytes.updateHeartRate(hrmCounter);
+        ble.gattServer().write(hrmRate.getValueHandle(), valueBytes.getPointer(), valueBytes.getNumValueBytes());
+    }
+
+    /**
+     * This callback allows the heart rate service to receive updates to the
+     * controlPoint characteristic.
+     *
+     * @param[in] params
+     *     Information about the characterisitc being updated.
+     */
+    virtual void onDataWritten(const GattWriteCallbackParams *params) {
+        if (params->handle == 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.
+             */
+        }
+    }
+
+protected:
+    void setupService(void) {
+        GattCharacteristic *charTable[] = {&hrmRate, &hrmLocation, &controlPoint};
+        GattService         hrmService(GattService::UUID_HEART_RATE_SERVICE, charTable, sizeof(charTable) / sizeof(GattCharacteristic *));
+
+        ble.addService(hrmService);
+        ble.onDataWritten(this, &HeartRateService::onDataWritten);
+    }
+
+protected:
+    /* Private internal representation for the bytes used to work with the value of the heart rate characteristic. */
+    struct HeartRateValueBytes {
+        static const unsigned MAX_VALUE_BYTES  = 3; /* Flags, and 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];
+    };
+
+protected:
+    BLE                 &ble;
+
+    HeartRateValueBytes  valueBytes;
+    uint8_t              controlPointValue;
+
+    GattCharacteristic                   hrmRate;
+    ReadOnlyGattCharacteristic<uint8_t>  hrmLocation;
+    WriteOnlyGattCharacteristic<uint8_t> controlPoint;
+};
+
+#endif /* #ifndef __BLE_HEART_RATE_SERVICE_H__*/