Bluetooth low energy, how to parse R-R Interval value?

Question

My application is receiving information from smart heart device. Now i can see pulse value. Could you please help me to parse R-R Interval value? How can i check device supp

Answer 1

Parse heart rate parameters in "C"

I uploaded the sample application to GitHub Heart-Rate-Bluegiga

void ble_evt_attclient_attribute_value(const struct ble_msg_attclient_attribute_value_evt_t *msg)
{
    if (msg->value.len < 2) {
        printf("Not enough fields in Heart Rate Measurement value");
        change_state(state_finish);
    }


    // Heart Rate Profile defined flags 
    const unsigned char HEART_RATE_VALUE_FORMAT = 0x01;
    const unsigned char ENERGY_EXPENDED_STATUS = 0x08;
    const unsigned char RR_INTERVAL = 0x10;


    unsigned char current_offset = 0;
    unsigned char flags = msg->value.data[current_offset];
    int is_heart_rate_value_size_long = ((flags & HEART_RATE_VALUE_FORMAT) != 0);
    int has_expended_energy = ((flags & ENERGY_EXPENDED_STATUS) != 0);
    int has_rr_intervals = ((flags & RR_INTERVAL) != 0);


    current_offset++;


    uint16 heart_rate_measurement_value = 0;


    if (is_heart_rate_value_size_long)
    {
        heart_rate_measurement_value = (uint16)((msg->value.data[current_offset + 1] << 8) +
            msg->value.data[current_offset]);
        current_offset += 2;
    }
    else
    {
        heart_rate_measurement_value = msg->value.data[current_offset];
        current_offset++;
    }


    printf("Heart rate measurment value: %d ", heart_rate_measurement_value);


    uint16 expended_energy_value = 0;


    if (has_expended_energy)
    {
        expended_energy_value = (uint16)((msg->value.data[current_offset + 1] << 8) +
            msg->value.data[current_offset]);
        current_offset += 2;


        printf(" Expended energy value: %d ", expended_energy_value);
    }


    uint16 rr_intervals[10] = {0};


    if (has_rr_intervals)
    {
        printf(" Rr intervals: ");


        int rr_intervals_count = (msg->value.len - current_offset) / 2;


        for (int i = 0; i < rr_intervals_count; i++)
        {
            int raw_rr_interval = (uint16)((msg->value.data[current_offset + 1] << 8) +
                msg->value.data[current_offset]);
            rr_intervals[i] = ((double)raw_rr_interval / 1024) * 1000;
            current_offset += 2;


            printf("%d ", rr_intervals[i]);
        }
        printf("\n");
    }
}