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/*
ds1338.h
DS1338 / DS1307 I2C clock module driver
Copyright 2012, 2014 Doug Szumski <d.s.szumski@gmail.com>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>
*/
/*
* A simple driver to interface with the DS1338. Should work with
* the pin compatible DS1307 too.
*
* TODO:
*
* > Read/write registers sequentially to/from an array.
* > Add a function to check the 'oscillator had a problem flag'
* > Add a function to configure the square wave output
* > Add a function to allow writing to additional NVRAM
* > Use bit fields to save RAM when storing time
*/
#ifndef DS1338_H
#define DS1338_H
/*
* Internal registers. Time is in BCD.
* See p10 of the DS1388 datasheet.
*/
#define DS1338_TWI_ADR 0xD0
#define DS1338_SECONDS 0x00
#define DS1338_MINUTES 0x01
#define DS1338_HOURS 0x02
#define DS1338_DAY 0x03
#define DS1338_DATE 0x04
#define DS1338_MONTH 0x05
#define DS1338_YEAR 0x06
#define DS1338_CONTROL 0x07
/*
* Seconds register flag - oscillator is enabled when
* this is set to zero. Undefined on startup.
*/
#define DS1338_CH 7
/*
* 12/24 hour select bit. When high clock is in 12 hour
* mode and the AM/PM bit is operational. When low the
* AM/PM bit becomes part of the tens counter for the
* 24 hour clock.
*/
#define DS1338_12_24_HR 6
/*
* AM/PM flag for 12 hour mode. PM is high.
*/
#define DS1338_AM_PM 5
// Control register settings: 1Hz square wave out
#define DS1338_CONTROL_SETTING 0b10010000
// 4kHz
//#define DS1338_CONTROL_SETTING 0b10010001
// 8 kHz
//#define DS1338_CONTROL_SETTING 0b10010010
// 32kHz
//#define DS1338_CONTROL_SETTING 0b10010011
// Generic BCD conversion. Don't use on seconds or hours.
#define UNPACK_BCD(x) (((x) & 0x0F) + ((x) >> 4) * 10)
#define TO_BCD(x) ((((x) / 10) << 4) + (x) % 10)
typedef struct ds1338_time_t
{
uint8_t seconds;
uint8_t minutes;
uint8_t hours;
uint8_t is_pm;
uint8_t day; // Runs from 0-6
uint8_t date;
uint8_t month;
uint8_t year;
} ds1338_time_t;
void
ds1338_init (void);
void
ds1338_get_time (ds1338_time_t * const time);
void
ds1338_set_time (const ds1338_time_t * const time);
#endif //DS1338_H
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