DS1307 RTC

[Mr-bkmtech]

Hi

I am looking to find, incorporate, or develop code to read and write to the DS1307 Real Time Clock.

Starting from scratch on this particular device so any help would be appreciated.

Thank you

[davefes]

https://awesome-micropython.com/#rtc

[Mr-bkmtech]

Thanks

I cloned this repository but am unsure how to implement this and integrate it into my existing code

https://github.com/brainelectronics/micropython-ds1307

[davefes]

Try copying ds1307.py to your flash file system and in your main program:
import ds1307
and then the example main.py:
https://github.com/brainelectronics/micropython-ds1307/blob/main/examples/main.py

[Mr-bkmtech]

Got the following error
Line 6
from eeprom import DS1307

Traceback (most recent call last):
File "", line 6, in
ImportError: no module named 'eeprom'

[davefes]

Why are you calling:
from eeprom import DS1307
Is there suppose to be a module called eeprom in RP2040?

As far as I am aware you have to copy something like ds1307.py to your filesystem then call it.
Are you trying to install the stuff at brainelectronics

Another one:
https://github.com/mcauser/micropython-tinyrtc-i2c

[davefes]

Something odd going on here. I am getting messages in my Gmail but they are not being displayed here.

I had a read through that distro and got a bit lost ... it seems more complicated than what I am use to. I haven't used mip.

However, I would copy https://github.com/brainelectronics/micropython-ds1307/blob/main/ds1307/ds1307.py to the flash and then use his https://github.com/brainelectronics/micropython-ds1307/blob/main/examples/main.py as a test script.

I searched through all his stuff and never saw eeprom anywhere. Where is that?

[Mr-bkmtech]

Hi

I have no idea how that file got corrupted. It should reference the file "ds1307"

Let me tell you where I am at.

I have 2 files, one is your main with the only change being a correction to the actual I2C pins used. And the associated library, if I am using the correct term.

I run the program and I get this

DS1307 is on I2C address 0x68
Weekday start is 0
Traceback (most recent call last):
File "", line 23, in
File "/lib/ds1307.py", line 125, in datetime
OSError: [Errno 5] EIO

Line 23 is in your main and is

print("Current RTC time: {}".format(ds1307.datetime))

Line 125 is

buf = self._i2c.readfrom_mem(self._addr, DATETIME_REG, 7)

Before we go much further I currently have no RTC connected, so is this error caused by that?

Tomorrow I can get an actual RTC hooked up.

[davefes]

I have 2 files, one is your main

I do not recall sending you any files. The links are not my work.

EIO does suggest that you need the RTC hooked up. Do that and then post the contents of the files that you are using and I will try to make suggestions. I have used the DS3231 not a DS1307.

[Mr-bkmtech]

Correct, they were just files you referred me too.

Here are my 2 files
The first is my "main" file

#!/usr/bin/env python3
# -*- coding: UTF-8 -*-

"""I2C EEPROM showcase"""

from ds1307 import DS1307
from machine import I2C, Pin
from time import gmtime, sleep, time
# The slave address byte contains the 7-bit DS1307
# address, which is 1101000b or 68h
I2C_ADDR = 0x68

# define custom I2C interface, default is 'I2C(0)'
# check the docs of your device for further details and pin infos
# this are the pins for the Raspberry Pi Pico adapter board
i2c = I2C(1, scl=Pin(3), sda=Pin(2), freq=800000)
ds1307 = DS1307(addr=I2C_ADDR, i2c=i2c)   # DS1307 on 0x68
# get LCD infos/properties
print("DS1307 is on I2C address 0x{0:02x}".format(ds1307.addr))
print("Weekday start is {}".format(ds1307.weekday_start))

# get the current RTC time
print("Current RTC time: {}".format(ds1307.datetime))

# set the RTC time to the current system time
now = gmtime(time())
ds1307.datetime = now

# Print the date and time in ISO8601 format: 2023-04-18T21:14:22
print("Today is {:04d}-{:02d}-{:02d}T{:02d}:{:02d}:{:02d}".format(
    ds1307.year, ds1307.month, ds1307.day,
    ds1307.hour, ds1307.minute, ds1307.second))

# check whether this year is a leap year
print("Is this year a leap year? {}".format(ds1307.is_leap_year(ds1307.year)))

# get the day of the year
print("Today is day {} of {}".format(
    ds1307.day_of_year(year=ds1307.year, month=ds1307.month, day=ds1307.day),
    ds1307.year))

# halt the oscillator
print("The oscillator is currently active at {}? {}".format(
    ds1307.datetime, ds1307.halt))
print("Halt the oscillator and wait for 5 seconds ...")
ds1307.halt = True
sleep(5)

print("Current RTC time: {}".format(ds1307.datetime))

print("Enable the oscillator and wait for 5 seconds ...")
ds1307.halt = False
sleep(5)
print("Current RTC time: {}".format(ds1307.datetime))

# control the squarewave pin SQ
print("Set square wave output to 1Hz and wait for 5 seconds ...")
ds1307.square_wave(sqw=1)
sleep(5)

print("Set square wave output to 4.096kHz and wait for 5 seconds ...")
ds1307.square_wave(sqw=4)
sleep(5)

print("Set square wave output to 8.192kHz and wait for 5 seconds ...")
ds1307.square_wave(sqw=8)
sleep(5)

print("Set square wave output to HIGH and wait for 5 seconds ...")
ds1307.square_wave(out=1)
sleep(5)

print("Set square wave output to LOW and wait for 5 seconds ...")
ds1307.square_wave(sqw=0)
sleep(5)

This is my second file

#!/usr/bin/env python3
# -*- coding: UTF-8 -*-

"""
I2C RTC driver for DS1307

https://github.com/mcauser/micropython-tinyrtc-i2c

MIT License
Copyright (c) 2018 Mike Causer
Extended 2023 by brainelectronics

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.

BCD Format:
https://en.wikipedia.org/wiki/Binary-coded_decimal
"""

# system packages
from machine import I2C
try:
    from micropython import const
except ImportError:
    def const(x):
        return x


class _Subscriptable():
    def __getitem__(self, item):
        return None


_subscriptable = _Subscriptable()

Optional = _subscriptable
Tuple = _subscriptable

DATETIME_REG = const(0)     # 0x00-0x06
CHIP_HALT = const(128)
CONTROL_REG = const(7)      # 0x07
RAM_REG = const(8)          # 0x08-0x3F

# The slave address byte contains the 7-bit DS1307
# address, which is 1101000b or 68d
class DS1307(object):
    """Driver for the DS1307 RTC."""

    def __init__(self, addr=0x68, i2c: Optional[I2C] = None) -> None:
        """
        Constructs a new instance

        :param      addr:   The I2C bus address of the EEPROM
        :type       addr:   int
        :param      i2c:    I2C object
        :type       i2c:    I2C
        """
        self._addr = addr

        if i2c is None:
            # default assignment, check the docs
            self._i2c = I2C(0)
        else:
            self._i2c = i2c

        self._weekday_start = 0
        self._halt = False

    @property
    def addr(self) -> int:
        """
        Get the DS1307 I2C bus address

        :returns:   DS1307 I2C bus address
        :rtype:     int
        """
        return self._addr

    @property
    def weekday_start(self) -> int:
        """
        Get the start of the weekday

        :returns:   Weekday start
        :rtype:     int
        """
        return self._weekday_start

    @weekday_start.setter
    def weekday_start(self, value: int) -> None:
        """Set the start of the weekday"""
        if 0 <= value <= 6:
            self._weekday_start = value
        else:
            raise ValueError("Weekday can only be in range 0-6")

    @property
    def datetime(self) -> Tuple[int, int, int, int, int, int, int, int]:
        """
        Get the current datetime

        (2023, 4, 18, 0, 10, 34, 4, 108)
        y,     m,  d, h, m,  s, wd, yd

        :returns:   (year, month, day, hour, minute, second, weekday, yearday)
        :rtype:     Tuple[int, int, int, int, int, int, int, int]
        """
        buf = bytearray(7)

        buf = self._i2c.readfrom_mem(self._addr, DATETIME_REG, 7)

        year = self._bcd_to_dec(buf[6]) + 2000
        month = self._bcd_to_dec(buf[5])
        day = self._bcd_to_dec(buf[4])
        yearday = self.day_of_year(year=year, month=month, day=day)
        return (
            year,
            month,
            day,
            self._bcd_to_dec(buf[2]),           # hour
            self._bcd_to_dec(buf[1]),           # minute
            self._bcd_to_dec(buf[0] & 0x7F),    # second
            self._bcd_to_dec(buf[3] - self._weekday_start),     # weekday
            yearday,
        )

    @datetime.setter
    def datetime(self, datetime: Tuple[int, int, int, int, int, int, int, int]) -> None:    # noqa: E501
        """
        Set datetime

        (2023, 4, 18, 20, 23, 38, 1, 108) by time.gmtime(time.time())
        y,     m,  d,  h, min,sec,wday, yday
        0,     1,  2,  3,  4,   5,   6, 7

        :param      datetime:  The datetime
        :type       datetime:  Tuple[int, int, int, int, int, int, int, int]
        """
        buf = bytearray(7)

        # msb = CH, 1 = halt, 0 = go
        buf[0] = self._dec_to_bcd(datetime[5]) & 0x7F   # second
        buf[1] = self._dec_to_bcd(datetime[4])  # minute
        buf[2] = self._dec_to_bcd(datetime[3])  # hour
        buf[3] = self._dec_to_bcd(datetime[6] + self._weekday_start)
        buf[4] = self._dec_to_bcd(datetime[2])  # day
        buf[5] = self._dec_to_bcd(datetime[1])  # month
        buf[6] = self._dec_to_bcd(datetime[0] - 2000)   # year

        if (self._halt):
            buf[0] |= (1 << 7)

        self._i2c.writeto_mem(self._addr, DATETIME_REG, buf)

    @property
    def year(self) -> int:
        """
        Get the year from the RTC

        :returns:   Year of RTC
        :rtype:     int
        """
        return self.datetime[0]

    @property
    def month(self) -> int:
        """
        Get the month from the RTC

        :returns:   Month of RTC
        :rtype:     int
        """
        return self.datetime[1]

    @property
    def day(self) -> int:
        """
        Get the day from the RTC

        :returns:   Day of RTC
        :rtype:     int
        """
        return self.datetime[2]

    @property
    def hour(self) -> int:
        """
        Get the hour from the RTC

        :returns:   Hour of RTC
        :rtype:     int
        """
        return self.datetime[3]

    @property
    def minute(self) -> int:
        """
        Get the minute from the RTC

        :returns:   Minute of RTC
        :rtype:     int
        """
        return self.datetime[4]

    @property
    def second(self) -> int:
        """
        Get the second from the RTC

        :returns:   Second of RTC
        :rtype:     int
        """
        return self.datetime[5]

    @property
    def weekday(self) -> int:
        """
        Get the weekday from the RTC

        :returns:   Weekday of RTC
        :rtype:     int
        """
        return self.datetime[5]

    @property
    def yearday(self) -> int:
        """
        Get the yearday from the RTC

        :returns:   Yearday of RTC
        :rtype:     int
        """
        return self.datetime[7]

    def is_leap_year(self, year: int) -> bool:
        """
        Determines whether the specified year is a leap year.

        :param      year:  The year
        :type       year:  int

        :returns:   True if the specified year is leap year, False otherwise.
        :rtype:     bool
        """
        return (year % 4 == 0)

    def day_of_year(self, year: int, month: int, day: int) -> int:
        """
        Get the day of the year

        :param      year:   The year
        :type       year:   int
        :param      month:  The month
        :type       month:  int
        :param      day:    The day
        :type       day:    int

        :returns:   Day of the year, January 1 is day 1
        :rtype:     int
        """
        month_days = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
        year -= 2000
        days16 = day

        for x in range(1, month):
            days16 += month_days[x - 1]

        if month >= 2 and self.is_leap_year(year=year):
            days16 += 1

        return days16

    @property
    def halt(self) -> bool:
        """
        Get status of DS1307

        :returns:   Status of DS1307
        :rtype:     bool
        """
        return self._halt

    @halt.setter
    def halt(self, value: bool = False) -> None:
        """
        Power up or power down the RTC oscillator

        :param      value:  The value
        :type       value:  bool
        """
        reg = self._i2c.readfrom_mem(self._addr, DATETIME_REG, 1)[0]

        if value:
            reg |= CHIP_HALT
        else:
            reg &= ~CHIP_HALT

        self._halt = bool(value)
        self._i2c.writeto_mem(self._addr, DATETIME_REG, bytearray([reg]))

    def square_wave(self, sqw: int = 0, out: int = 0) -> None:
        """
        Output square wave on pin SQ

        at 1Hz, 4.096kHz, 8.192kHz or 32.768kHz, or disable the oscillator
        and output logic level high/low.
        """
        if sqw not in (0, 1, 4, 8, 32):
            raise ValueError(
                "Squarewave can be set to 0Hz, 1Hz, {}Hz, {}Hz or {}Hz".format(
                    2 ** 12, 2 ** 13, 2 ** 15)
            )

        rs0 = 1 if sqw == 4 or sqw == 32 else 0
        rs1 = 1 if sqw == 8 or sqw == 32 else 0
        out = 1 if out > 0 else 0
        sqw = 1 if sqw > 0 else 0

        reg = rs0 | rs1 << 1 | sqw << 4 | out << 7

        self._i2c.writeto_mem(self._addr, CONTROL_REG, bytearray([reg]))

    def _dec_to_bcd(self, value: int) -> int:
        """
        Convert decimal to binary coded decimal (BCD) format

        :param      value:  The value
        :type       value:  int

        :returns:   Binary coded decimal (BCD) format
        :rtype:     int
        """
        return (value // 10) << 4 | (value % 10)

    def _bcd_to_dec(self, value: int) -> int:
        """
        Convert binary coded decimal (BCD) format to decimal

        :param      value:  The value
        :type       value:  int

        :returns:   Decimal value
        :rtype:     int
        """
        return ((value >> 4) * 10) + (value & 0x0F)

[davefes]

Have you connected up the DS1307?

[Mr-bkmtech]

Hello

Sorry for the delay in getting back to you.

I ran the code above and this was the result.

DS1307 is on I2C address 0x68
Weekday start is 0
Current RTC time: (2000, 1, 1, 0, 0, 0, 1, 1)
Today is 2023-06-29T16:35:13
Is this year a leap year? False
Today is day 180 of 2023
The oscillator is currently active at (2023, 6, 29, 16, 35, 13, 3, 180)? False
Halt the oscillator and wait for 5 seconds ...

[davefes]

Looks hopeful. I wonder if the last two lines suggest that you need to tell the RTC what time it is? Surprised that you appear only have a 5 second window to do it in!

For a DS3231 I do:

    epoch = utime.time()
    local_time = utime.localtime(epoch)
    seconds = local_time[5]
    minutes = local_time[4]
    hours = local_time[3]
    day = local_time[2]
    month = local_time[1]
    year = local_time[0]

     #  update the DS3231 with the current time
     #  set time with individual set functions
        rtc.setYear(year)
        rtc.setMonth(month)
        rtc.setDay(day)
        rtc.setHour(hours)
        rtc.setMinutes(minutes)
        rtc.setSeconds(seconds)

[bidrohini]

Here is a full tutorial on how to read the DS1307 using micropython. This one has used Raspberry pi pico and Thonny IDE. This may help:

https://youtu.be/DWCu-rhy4jQ

In case you need the DS1307 datasheet, specs everything together, you can save this link:

https://www.theengineeringprojects.com/2019/04/introduction-to-ds1307.html