File content as of revision 71:7b6a488af957:

/* 
 * Copyright (c) 2015 Robert Walker
 *
 * 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_CYCLING_SPEED_AND_CADENCE_SERVICE_H__
#define __BLE_CYCLING_SPEED_AND_CADENCE_SERVICE_H__

#include "ble/BLE.h"

/**
* @class CyclingSpeedAndCadenceService
* @brief BLE Service for Cycling Speed and Cadence. This BLE Service contains the location of the sensor, the total wheel revolutions, total crank revolutiosn. <br>
* Service:  https://developer.bluetooth.org/gatt/services/Pages/ServiceViewer.aspx?u=org.bluetooth.service.cycling_speed_and_cadence.xml <br>
* CSC Char: https://developer.bluetooth.org/gatt/characteristics/Pages/CharacteristicViewer.aspx?u=org.bluetooth.characteristic.csc_measurement.xml <br>
* Location: https://developer.bluetooth.org/gatt/characteristics/Pages/CharacteristicViewer.aspx?u=org.bluetooth.characteristic.sensor_location.xml
*/
class CyclingSpeedAndCadenceService {
public:
    /**
    * @enum SensorLocation
    * @brief Location of sensor on bike.
    */
    enum {
        LOCATION_OTHER,        /*!< Other */
        LOCATION_TOP_OF_SHOE,  /*!< Top of shoe */
        LOCATION_IN_SHOE,      /*!< In shoe */
        LOCATION_HIP,          /*!< Hip */
        LOCATION_FRONT_WHEEL,  /*!< Front Wheel */
        LOCATION_LEFT_CRANK,   /*!< Left Crank */
        LOCATION_RIGHT_CRANK,  /*!< Right Crank */
        LOCATION_LEFT_PEDAL,   /*!< Left Pedal */
        LOCATION_RIGHT_PEDAL,  /*!< Right Pedal */
        LOCATION_FRONT_HUB,    /*!< Front Hub */
        LOCATION_REAR_DROPOUT, /*!< Rear Dropout */
        LOCATION_CHAINSTAY,    /*!< Chainstay */
        LOCATION_REAR_WHEEL,   /*!< Rear Wheel */
        LOCATION_REAR_HUB,     /*!< Rear Hub */
        LOCATION_CHEST,        /*!< Chest */
    };
    
    enum {
        UUID_SENSOR_LOCATION_CHAR = 0x2A5D,
        UUID_SC_CONTROL_POINT_CHAR = 0x2A55
    };

public:
    /**
     * @brief Constructor with initial counter values.
     *
     * @param[ref] _ble
     *               Reference to the underlying BLE.
     * @param[in] wheelCounter (32-bit)
     *               initial value for the wheel counter.
     * @param[in] crankCounter (32-bit)
     *               initial value for the crank counter.
     * @param[in] location
     *               Sensor's location.
     */
    CyclingSpeedAndCadenceService(BLE &_ble, uint8_t location) :
        ble(_ble),
        csc(GattCharacteristic::UUID_CSC_MEASUREMENT_CHAR, valueBytes.getPointer(),
            valueBytes.getNumValueBytes(), SpeedCadenceValueBytes::MAX_BYTES,
            GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_READ | GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_NOTIFY),
        scLocation(UUID_SENSOR_LOCATION_CHAR, &location),
        controlPoint(UUID_SC_CONTROL_POINT_CHAR, &controlPointValue) {
        setupService();
    }

    /**
     * @brief Set a new value for wheel revolutions.
     *
     * @param[in] wheelCounter
     *                  Total wheel revolutions.
     * @param[in] eventTime
     *                  Time of event.
     */
    void updateWheelCounter(uint32_t wheelCounter, uint16_t eventTime) {
        valueBytes.updateWheelCounter(wheelCounter, eventTime);
        ble.gattServer().write(csc.getValueHandle(), valueBytes.getPointer(), valueBytes.getNumValueBytes());
    }

    /**
     * @brief Set a new value for crank revolutions.
     *
     * @param[in] crankCounter
     *                  Total crank revolutions.
     * @param[in] eventTime
     *                  Time of event.
     */
    void updateCrankCounter(uint16_t crankCounter, uint16_t eventTime) {
        valueBytes.updateCrankCounter(crankCounter, eventTime);
        ble.gattServer().write(csc.getValueHandle(), valueBytes.getPointer(), valueBytes.getNumValueBytes());
    }

    void updateCounters(uint32_t wheelCounter, uint16_t crankCounter, uint16_t eventTime) {
        valueBytes.updateWheelCounter(wheelCounter, eventTime);
        valueBytes.updateCrankCounter(crankCounter, eventTime);
        ble.gattServer().write(csc.getValueHandle(), valueBytes.getPointer(), valueBytes.getNumValueBytes());
    }

    /**
     * This callback allows the CyclingSpeedAndCadenceService 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[] = {&csc, &scLocation, &controlPoint};
        GattService         cscService(GattService::UUID_CYCLING_SPEED_AND_CADENCE, charTable, sizeof(charTable) / sizeof(GattCharacteristic *));

        ble.addService(cscService);
        ble.onDataWritten(this, &CyclingSpeedAndCadenceService::onDataWritten);
    }

protected:
    /* Private internal representation for the bytes used to work with the value of the speed cadence characteristic. */
    struct SpeedCadenceValueBytes {
        static const uint16_t MAX_BYTES = (1 + 4 + 2 + 2 + 2);
        static const uint8_t FLAG_WHEEL_PRESENT = (1 << 0);
        static const uint8_t FLAG_CRANK_PRESENT = (1 << 1);

        SpeedCadenceValueBytes()
            : flags(0)
        {
            updateWheelCounter(1, 0);
            updateCrankCounter(1, 0);
        }

        void updateWheelCounter(uint32_t _wheelCounter, uint16_t _when) {
            flags |= FLAG_WHEEL_PRESENT;
            wheelCounter = _wheelCounter;
            lastWheelEvent = _when;
        }

        void updateCrankCounter(uint16_t _crankCounter, uint16_t _when) {
            flags |= FLAG_CRANK_PRESENT;
            crankCounter = _crankCounter;
            lastCrankEvent = _when;
        }

        uint8_t       *getPointer(void) {
            pack();
            return valueBytes;
        }

        const uint8_t *getPointer(void) const {
            pack();
            return valueBytes;
        }

        unsigned       getNumValueBytes(void) const {
            return 1 +
                ((flags & FLAG_WHEEL_PRESENT) ? (4+2) : 0) +
                ((flags & FLAG_CRANK_PRESENT) ? (2+2) : 0);
        }

    private:
        void pack() const
        {
            valueBytes[0] = flags;
            uint8_t* p = &valueBytes[1];
            if (flags & FLAG_WHEEL_PRESENT)
            {
                *(uint32_t*)(p) = wheelCounter;
                p += 4;
                *(uint16_t*)(p) = lastWheelEvent;
                p += 2;
            }
            if (flags & FLAG_CRANK_PRESENT)
            {
                *(uint16_t*)(p) = crankCounter;
                p += 2;
                *(uint16_t*)(p) = lastCrankEvent;
                p += 2;
            }
        }
        
        uint8_t flags;
        uint32_t wheelCounter;
        uint16_t lastWheelEvent;
        uint16_t crankCounter;
        uint16_t lastCrankEvent;
        mutable uint8_t valueBytes[MAX_BYTES];
    };

protected:
    BLE                 &ble;

    SpeedCadenceValueBytes  valueBytes;
    uint8_t              controlPointValue;

    GattCharacteristic                   csc;
    ReadOnlyGattCharacteristic<uint8_t>  scLocation;
    WriteOnlyGattCharacteristic<uint8_t> controlPoint;
};

#endif /* #ifndef __BLE_CYCLING_SPEED_AND_CADENCE_SERVICE_H__*/