File content as of revision 2:64cead334a4c:

#include "BLE.h"
//#include "Gap.h"

/*
* @This example can be demonstrated with Blood Pressure Android App downloaded from
* @https://github.com/Marcomissyou/BluetoothLeBooldPressure.git
* @Author: Marco.Hsu  
* @Email: marco.missyou@gmail.com 
*/
class BloodPressureService {
public:
    BloodPressureService(BLEDevice &_ble, float Systolic, float Diastolic, float mean_arterial, uint16_t BloodFeature):
        ble(_ble),
        BloodPressureValue(Systolic, Diastolic, mean_arterial),
        BloodFeatureValue(BloodFeature),
        //GlucoseFeatureValue(GluFeature),
        BloodPressureGatt(GattCharacteristic::UUID_BLOOD_PRESSURE_MEASUREMENT_CHAR, BloodPressureValue.getPointer(),
                sizeof(uint8_t), BloodPressureStruc::MAX_VALUE_BYTES, GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_INDICATE),
        BloodFeature(GattCharacteristic::UUID_BLOOD_PRESSURE_FEATURE_CHAR, &BloodFeatureValue) {
            setupService();
        }

    void updateBloodPressureMeasurement(float Systolic, float Diastolic, float mean_arterial) {
        BloodPressureValue.uploadBloodPressureValue(Systolic, Diastolic, mean_arterial);
        ble.updateCharacteristicValue(BloodPressureGatt.getValueAttribute().getHandle(), BloodPressureValue.getPointer(), 6);
    }
    
    

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[] = {&BloodPressureGatt, &BloodFeature};
        GattService         BloodService(GattService::UUID_BLOOD_PRESSURE_SERVICE, charTable, sizeof(charTable) / sizeof(GattCharacteristic *));

        ble.addService(BloodService);
        serviceAdded = true;

    }

//==========================================================================================================
private:
struct BloodPressureStruc {
        static const unsigned MAX_VALUE_BYTES  = 8; 
        static const unsigned FLAGS_BYTE_INDEX = 0;
        
        static const unsigned Blood_Pressure_Units_Flag = 0;    // 0 in units of mmHg, 1 in units of kPa
        static const unsigned Time_Stamp_Flag = 0;              //
        static const unsigned Pulse_Rate_Flag = 0;
        static const unsigned User_ID_Flag = 0;
        static const unsigned Measurement_Status_Flag = 0;
         
        static const unsigned VALUE_FORMAT_BITNUM = 0;
        static const uint8_t  VALUE_FORMAT_FLAG   = 0;
        
        // Initial setting Blood Pressure measurement value
        BloodPressureStruc(float Systolic, float Diastolic, float mean_arterial) : BloodPressureValue() { 
            uploadBloodPressureValue(Systolic, Diastolic, mean_arterial);
        }
        
        // function to update Blood Pressure measurement value in unit of mmHg
        void uploadBloodPressureValue(float Systolic, float Diastolic, float mean_arterial) {
            uint16_t ieee11073_Systolic = ieee11073_float16(Systolic);
            uint16_t ieee11073_Diastolic = ieee11073_float16(Diastolic);
            uint16_t ieee11073_mean_arterial = ieee11073_float16(mean_arterial);
            BloodPressureValue[FLAGS_BYTE_INDEX]    = (Blood_Pressure_Units_Flag << 0)|(Time_Stamp_Flag << 1)|
                                                      (Pulse_Rate_Flag << 2)|(User_ID_Flag << 3)|(Measurement_Status_Flag << 4);
            //memcpy(&BloodPressureValue[FLAGS_BYTE_INDEX], &ieee11073_Systolic, 2);
            //memcpy(&BloodPressureValue[FLAGS_BYTE_INDEX+2], &ieee11073_Diastolic, 2);
            //memcpy(&BloodPressureValue[FLAGS_BYTE_INDEX+4], &ieee11073_mean_arterial, 2);
            BloodPressureValue[FLAGS_BYTE_INDEX + 1] = (uint8_t)(ieee11073_Systolic &0xff); 
            BloodPressureValue[FLAGS_BYTE_INDEX + 2] = (uint8_t)(ieee11073_Systolic >> 8); 
            BloodPressureValue[FLAGS_BYTE_INDEX + 3] = (uint8_t)(ieee11073_Diastolic &0xff); 
            BloodPressureValue[FLAGS_BYTE_INDEX + 4] = (uint8_t)(ieee11073_Diastolic >> 8); 
            BloodPressureValue[FLAGS_BYTE_INDEX + 5] = (uint8_t)(ieee11073_mean_arterial &0xff); 
            BloodPressureValue[FLAGS_BYTE_INDEX + 6] = (uint8_t)(ieee11073_mean_arterial >>8); 
        }


        uint8_t       *getPointer(void) {
            return BloodPressureValue;
        }
        
        const uint8_t *getPointer(void) const {
            return BloodPressureValue;
        }
        
        uint16_t ieee11073_float16(float BloodPressure) {
            uint8_t  exponent = 0; 
            uint16_t mantissa = (uint16_t)BloodPressure;
            return ((exponent << 12)&0xF0) | (mantissa << 0) & 0x0FFF ;
        }
private:
        uint8_t BloodPressureValue[MAX_VALUE_BYTES];
};

        
private:
    BLEDevice           &ble;
    
    BloodPressureStruc          BloodPressureValue;
    GattCharacteristic          BloodPressureGatt;  // data carrier 

    uint16_t                    BloodFeatureValue;
    ReadOnlyGattCharacteristic<uint16_t>  BloodFeature;
    
};