DS3231.h

/*
 * MIT License
 *
 * Copyright (c) 2020 Christopher B. Liebman
 *
 * 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.
*/

#ifndef _DS3231_H
#define _DS3231_H

#include <driver/i2c.h>
#include <freertos/semphr.h>
#include <time.h>

class DS3231
{
public:
    enum SquareWave
    {
        SQWAVE_1HZ    = 0x00,
        SQWAVE_1024HZ = 0x08,
        SQWAVE_4096HZ = 0x10,
        SQWAVE_8192HZ = 0x18
    };

    DS3231(i2c_port_t i2c = I2C_NUM_0);
    virtual ~DS3231();
    bool begin();
    
    bool getTime(struct tm* tm);
    bool setTime(struct tm* tm);

    int8_t getAgeOffset();
    bool setAgeOffset(int8_t ageoff);

protected:
    const uint8_t DS3231_ADDR       = 0x68;
    const uint8_t DS3231_12HR       = 0x40;
    const uint8_t DS3231_PM         = 0x20;
    const uint8_t DS3231_12HR_MASK  = 0x1f;
    const uint8_t DS3231_MONTH_MASK = 0x1f;
    enum  Register : uint8_t
    {
        SECONDS    = 0x00,
        MINUTES    = 0x01,
        HOURS      = 0x02,
        DAY        = 0x03,
        DATE       = 0x04,
        MONTH      = 0x05,
        YEAR       = 0x06,
        A1_SECONDS = 0x07,
        A1_MINUTES = 0x08,
        A1_HOURS   = 0x09,
        A1_DAYDATE = 0x0a,
        A2_MINUTES = 0x0b,
        A2_HOURS   = 0x0c,
        A2_DAYDATE = 0x0d,
        CONTROL    = 0x0e,
        STATUS     = 0x0f,
        AGEOFFSET  = 0x10,
        TEMP_MSB   = 0x11,
        TEMP_LSB   = 0x12,
        REG_CNT,
    };

    enum Control : uint8_t
    {
        EOSC        = 0x80,
        BBSQW       = 0x40,
        CONV        = 0x20,
        SQWAVE_MASK = 0x18,
        INTCN       = 0x04,
        ALARM_2_EN  = 0x02,
        ALARM_1_EN  = 0x01
    };

    enum Status : uint8_t
    {
        OSC_STOP_FLAG = 0x80,
        EN32KHZ       = 0x08,
        BUSY          = 0x04,
        ALARM_2_FLAG  = 0x02,
        ALARM_1_FLAG  = 0x01
    };

    bool updateReg(Register reg, uint8_t value, uint8_t mask);
    bool writeReg(Register reg, uint8_t value);
    bool write(Register reg, size_t len, uint8_t* value);
    bool readReg(Register reg, uint8_t* value);
    bool read(Register reg, size_t len, uint8_t* value);
private:
    i2c_port_t         _i2c;
    SemaphoreHandle_t  _lock = nullptr;
    int8_t             _age_offset = 0;
};

#endif // _DS3231_H