Htu21dDrv.cpp

/**
 * \file Htu21dDrv.cpp
 *
 *  Created by Scott Erholm on 6/14/16.
 *  Copyright (c) 2016 Agilatech. All rights reserved.
 *
 *  Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 
 * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */

#include "Htu21dDrv.h"

Htu21dDrv::Htu21dDrv(std::string devfile, uint32_t addr):i2cbus::I2CDevice(devfile,addr) {
    
    if (initialize()) {
        this->active = true;
    }
    else {
        std::cerr << name << " did not initialize. " << name << " is inactive" << std::endl;
    }
    
}

std::string Htu21dDrv::getVersion() {
    return name + " " + version;
}

std::string Htu21dDrv::getDeviceName() {
    return name;
}

std::string Htu21dDrv::getDeviceType() {
    return type;
}

int Htu21dDrv::getNumValues() {
    return numValues;
}

std::string Htu21dDrv::getTypeAtIndex(int index) {
    if ((index < 0) || (index > (numValues - 1))) {
        return "none";
    }
    
    return valueTypes[index];
}

std::string Htu21dDrv::getNameAtIndex(int index) {
    if ((index < 0) || (index > (numValues - 1))) {
        return "none";
    }
    
    return valueNames[index];
}

bool Htu21dDrv::isActive() {
    return this->active;
}

std::string Htu21dDrv::getValueByName(std::string name) {
    
    for (int i = 0; i < numValues; i++) {
        if (name == valueNames[i]) {
            return this->getValueAtIndex(i);
        }
    }
    
    return "none";
}

std::string Htu21dDrv::getValueAtIndex(int index) {
    
    if (!this->active) {
        return "none";
    }

    if (index == 0) {
        return this->readValue0();
    }
    else if (index == 1) {
        return this->readValue1();
    }
    else {
        return "none";
    }
    
}

bool Htu21dDrv::initialize() {
    
    this->reset();
    
    /* Make sure we're actually connected */
    uint8_t x = readRegister(HTDU21D_READREG);
    if (!(x & 0x2)) {
        return false;
    }
    
    return true;
}

std::string Htu21dDrv::readValue0() {
    
    if (!this->active) {
        return "none";
    }
    
    unsigned char *hum = read3Bytes(HTDU21D_READHUM);
    
    unsigned int rawHumidity = ((unsigned int) hum[0] << 8) | (unsigned int) hum[1];
    
    // crc is hum[2]
    
    float retHum = rawHumidity;
    retHum *= 125;
    retHum /= 65536;
    retHum -= 6;
    
    // convert the float to a string with 1 decimal place
    return DataManip::dataToString(retHum, 1);
}

std::string Htu21dDrv::readValue1() {
    
    if (!this->active) {
        return "none";
    }
    
    unsigned char *tmp = read3Bytes(HTDU21D_READTEMP);
    
    unsigned int temp = ((unsigned int) tmp[0] << 8) | (unsigned int) tmp[1];
    
    // crc is tmp[2]
    
    float retTemp = temp;
    retTemp *= 175.72;
    retTemp /= 65536;
    retTemp -= 46.85;
    
    // convert the float to a string with 1 decimal place
    return DataManip::dataToString(retTemp, 1);
}

void Htu21dDrv::reset(void) {
    
    write(HTDU21D_RESET);
    
    usleep(15000);
}

unsigned char* Htu21dDrv::read3Bytes(uint32_t fromAddress){
    this->write(fromAddress);
    unsigned char* data = new unsigned char[3];
    
    // Wait 50ms for the measurement to be taken
    usleep(50000);
    
    if(::read(this->file, data, 3)!=(int)3){
        DPRINT("Htu21dDrv: Failed to read in the full buffer.\n");
        return NULL;
    }
    return data;
}