DS3231_for_STM32_HAL

An STM32 HAL library for the DS3231 real-time clock IC.

Quick start

Minimal setup

STM32CubeMX setup

In STM32CubeMX, set I2C1 to "I2C" and USART1 to "asynchronous"
Set up an external interrupt pin (say PB0) in GPIO settings, use "external interrupt mode with falling edge trigger detection" and "pull-up" settings.
Activate the external interrupt in NVIC settings by checking the corresponding box.
Connect pin 3 (INT#/SQW) of the DS3231 to this external interrupt pin.
Save and generate code.

IDE setup

In your IDE, include ds3231_for_stm32_hal.h and ds3231_for_stm32_hal.c.

Main program

Includes

In main.c (main program body file), include:

#include "ds3231_for_stm32_hal.h"

Initialization

Initialization function:

void DS3231_Init(I2C_HandleTypeDef *hi2c);

In main.c, before the main loop and after the system inits, call the DS3231 init function, and pass the corresponding I2C handle:

DS3231_Init(&hi2c1);

Date and time settings

Date functions:

void DS3231_SetDayOfWeek(uint8_t dow); // <-- Number of days since Sunday, 1 to 7.
void DS3231_SetDate(uint8_t date);
void DS3231_SetMonth(uint8_t month);
void DS3231_SetYear(uint16_t year);
void DS3231_SetFullDate(uint8_t date, uint8_t month, uint8_t dow, uint16_t year);

Time functions:

void DS3231_SetHour(uint8_t hour_24mode);
void DS3231_SetMinute(uint8_t minute);
void DS3231_SetSecond(uint8_t second);
void DS3231_SetFullTime(uint8_t hour_24mode, uint8_t minute, uint8_t second);

Interrupt modes

Set interrupt mode with:

void DS3231_SetInterruptMode(DS3231_InterruptMode mode);

Options: square wave interrupt and alarm interrupt.

typedef enum DS3231_InterruptMode{
    DS3231_SQUARE_WAVE_INTERRUPT, DS3231_ALARM_INTERRUPT
}DS3231_InterruptMode;

Square wave output

With square wave interrupt mode selected, select interrupting rate with:

void DS3231_SetRateSelect(DS3231_Rate rate);

Options: 1 Hz, 1.024 kHz, 4.096 kHz or 8.912 kHz.

typedef enum DS3231_Rate{
	DS3231_1HZ, DS3231_1024HZ, DS3231_4096HZ, DS3231_8192HZ
}DS3231_Rate;

Alarms

With alarm interrupt mode selected, enable/disable alarms with:

void DS3231_EnableAlarm1(DS3231_State enable);
void DS3231_EnableAlarm2(DS3231_State enable);

Set alarm mode with:

void DS3231_SetAlarm1Mode(DS3231_Alarm1Mode alarmMode);
void DS3231_SetAlarm2Mode(DS3231_Alarm2Mode alarmMode);

Options modes: (refer to table 2 of datasheets):

typedef enum D3231_Alarm1Mode{
    DS3231_A1_EVERY_S = 0x0f, DS3231_A1_MATCH_S = 0x0e, DS3231_A1_MATCH_S_M = 0x0c,
    DS3231_A1_MATCH_S_M_H = 0x08, DS3231_A1_MATCH_S_M_H_DATE = 0x00, DS3231_A1_MATCH_S_M_H_DAY = 0x80,
}DS3231_Alarm1Mode;

typedef enum D3231_Alarm2Mode{
    DS3231_A2_EVERY_M = 0x07, DS3231_A2_MATCH_M = 0x06, DS3231_A2_MATCH_M_H = 0x04,
    DS3231_A2_MATCH_M_H_DATE = 0x00, DS3231_A2_MATCH_M_H_DAY = 0x80,
}DS3231_Alarm2Mode;

Interrupts

Includes

In stm32f*xx_it.c (interrupt service routine file), include:

#include "ds3231_for_stm32_hal.h"

Checking for an alarm

Check for an alarm flag with:

uint8_t DS3231_IsAlarm1Triggered();
uint8_t DS3231_IsAlarm2Triggered();

Clearing an alarm

Clear an alarm flag with:

void DS3231_ClearAlarm1Flag();
void DS3231_ClearAlarm2Flag();

Misc

Enable 32kHz output:

void DS3231_Enable32kHzOutput(DS3231_State enable);

Check for status:

uint8_t DS3231_IsOscillatorStopped();
uint8_t DS3231_Is32kHzEnabled();

Temperature functions:

int8_t DS3231_GetTemperatureInteger();
uint8_t DS3231_GetTemperatureFraction();

Refer to ./examples (main.c, stm32f4xx_it.c) and datasheets for further information.

License

eepj/stm32-ds3231

ErrorLooks like something went wrong!

About

Topics

Resources

License

Uh oh!

Stars

Watchers

Forks

Releases

Packages 0

Languages

Error
Looks like something went wrong!

Packages