File content as of revision 2:6f76d6160601:

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#ifndef __BLE_CHARACTERISTIC_H__
#define __BLE_CHARACTERISTIC_H__

#include "mbed.h"
#include "BLE.h"

/**
 * @class   Characteristic
 * @brief   Abstract characteristic class.
 * @details Implement sub class derived from this for custom characteristic.
 */
class Characteristic
{
public:

    static const unsigned TIMESTAMP_BYTES = 7;

    virtual GattCharacteristic *getChar(void) = 0;
    virtual uint8_t getNumBytes(void) = 0;
    virtual uint8_t *getBytes(void) = 0;

protected:

    // Convert time_t to the timestamp format
    static void date_time(time_t time, uint8_t *buf) {
        // Convert time_t to Year, Month, Day, Hour, Minute, Second
        struct tm ts = *localtime(&time);

        buf[1] = ((ts.tm_year+1900) & 0xFF00) >> 8;
        buf[0] = (ts.tm_year+1900) & 0xFF;

        buf[2] = (ts.tm_mon + 1) & 0xFF;
        buf[3] = ts.tm_mday & 0xFF;
        buf[4] = ts.tm_hour & 0xFF;
        buf[5] = ts.tm_min & 0xFF;
        buf[6] = ts.tm_sec & 0xFF;
    }

    // Convert floating point numbers to IEEE-11073 32-bit float
    static uint32_t float_bytes(float _float, uint8_t exp) {
        // Calculate how much to adjust mantissa
        uint8_t exponent = 0xFF - exp + 1;
        while(exp > 0) {
            _float *=10;
            exp--;
        }
        uint32_t mantissa = (uint32_t)(_float);
        return (((uint32_t)exponent) << 24) | mantissa;
    }
};

#endif /* #ifndef __BLE_CHARACTERISTIC_H__*/