VRS/PressureSensor.cpp

#include "PressureSensor.h"
#include "Modbus.h"

PressureSensor::PressureSensor(SerialUi* pSerial)
{
    m_pSerial = pSerial;
}

bool PressureSensor::Read(float& pressure)
{
    QByteArray tx_buf;

    char zero = 0x00;
    tx_buf.append(PRESSURESENSOR_ADDRESS);
    tx_buf.append(0x04);
    tx_buf.append(zero);
    tx_buf.append(zero);
    tx_buf.append(zero);
    tx_buf.append(0x02);

    unsigned short crc;

    crc=CRC16_MODBUS((unsigned char *)tx_buf.data(),tx_buf.size());

    tx_buf.append((crc>>8)&0xff);
    tx_buf.append(crc&0xff);

    QByteArray rx_buf;
    rx_buf = m_pSerial->serialWriteReponse(tx_buf);
    if(rx_buf.size() > 0){
        if(check_crc(rx_buf)){

            char value[4];
            value[3] = rx_buf.at(5);
            value[2] = rx_buf.at(6);
            value[1] = rx_buf.at(3);
            value[0] = rx_buf.at(4);

            float* p = (float*)value;
            pressure = *p;

            return true;
        }else{

            qDebug("PressureSensor::Read <<< check crc failed");
            return false;
        }

    }else{

        qDebug("PressureSensor::Read <<< no data received");
        return false;
    }
}

bool PressureSensor::Set_Zero()
{
    QByteArray tx_buf;

    char zero = 0x00;
    tx_buf.append(PRESSURESENSOR_ADDRESS);
    tx_buf.append(0x06);
    tx_buf.append(zero);
    tx_buf.append(0x1E);
    tx_buf.append(zero);
    tx_buf.append(0x01);

    unsigned short crc;

    crc=CRC16_MODBUS((unsigned char *)tx_buf.data(),tx_buf.size());

    tx_buf.append((crc>>8)&0xff);
    tx_buf.append(crc&0xff);

    QByteArray rx_buf;
    rx_buf = m_pSerial->serialWriteReponse(tx_buf);
    if(rx_buf.size() > 0){
        if(check_crc(rx_buf)){

            return true;
        }else{
            qDebug("PressureSensor::Set_Zero <<< check crc failed");
            return false;
        }
    }else{
        qDebug("PressureSensor::Set_Zero <<< no data received");
        return false;
    }
}

bool PressureSensor::check_crc(QByteArray data)
{
    int size = data.size();
    unsigned short crc1 =0, crc2= 0;

    unsigned char crc_h = data.at(size-2);
    unsigned char crc_l = data.at(size-1);

    crc1 = (crc_h <<8) |crc_l;
    crc2 = CRC16_MODBUS((unsigned char *)data.data(),data.size()-2);

     if(crc1 == crc2){
        return true;
     }else{
         return false;
     }
}