hwxpxx.h

/*
 * Author: Jon Trulson <jtrulson@ics.com>
 * Copyright (c) 2016 Intel Corporation.
 *
 * 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.
 */
#pragma once

#include <string>

#include <modbus/modbus.h>

namespace upm {

  class HWXPXX {
  public:
    // MODBUS input registers
    typedef enum {
      INPUT_HUMIDITY                        = 0x0000,
      // optional temp sensor
      INPUT_TEMPERATURE                     = 0x0001,
      // optional slider input
      INPUT_SLIDER                          = 0x0002
    } INPUT_REGS_T;

    // MODBUS coil registers
    typedef enum {
      // device reports in C or F?
      COIL_TEMP_SCALE                       = 0x0000,

      // optional override button status
      COIL_OVERRIDE                         = 0x0001
    } COIL_REGS_T;

    // MODBUS holding registers
    typedef enum {
      HOLDING_TEMP_OFFSET                   = 0x0000,
      HOLDING_HUM_OFFSET                    = 0x0001
    } HOLDING_REGS_T;

    HWXPXX(std::string device, int address, int baud=19200, int bits=8,
          char parity='N', int stopBits=2);

    ~HWXPXX();

    void update();

    float getTemperature(bool fahrenheit=false);

    float getHumidity();

    int getSlider();

    bool getOverrideSwitchStatus();

    void clearOverrideSwitch();

    int getTemperatureOffset();

    int getHumidityOffset();

    void setTemperatureOffset(int offset);

    void setHumidityOffset(int offset);

    void setTemperatureScale(bool fahrenheit);

    std::string getSlaveID();

    void setSlaveAddress(int addr);

    void setDebug(bool enable);

  protected:
    // input registers
    int readInputRegs(INPUT_REGS_T reg, int len, uint16_t *buf);
    uint16_t readInputReg(INPUT_REGS_T reg);

    // coils
    int readCoils(COIL_REGS_T reg, int numBits, uint8_t *buf);
    bool readCoil(COIL_REGS_T reg);
    void writeCoil(COIL_REGS_T reg, bool val);

    // holding registers
    int readHoldingRegs(HOLDING_REGS_T reg, int len, uint16_t *buf);
    uint16_t readHoldingReg(HOLDING_REGS_T reg);
    void writeHoldingReg(HOLDING_REGS_T reg, int value);

    // MODBUS context
    modbus_t *m_mbContext;

    // is the device reporting in C or F?
    bool m_isCelcius;

  private:
    bool m_debugging;

    // data
    float m_temperature;
    float m_humidity; // relative
    int m_slider; // optional slider value
    bool m_override; // status of override switch
  };
}