# The MIT License (MIT)
#
# Copyright (c) 2016 Scott Shawcroft for Adafruit Industries
#
# 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.
# pylint: disable=too-few-public-methods
"""
`adafruit_register.i2c_bcd_alarm`
====================================================
Binary Coded Decimal alarm register
* Author(s): Scott Shawcroft
"""
__version__ = "0.0.0-auto.0"
__repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_Register.git"
import time
def _bcd2bin(value):
"""Convert binary coded decimal to Binary
:param value: the BCD value to convert to binary (required, no default)
"""
return value - 6 * (value >> 4)
def _bin2bcd(value):
"""Convert a binary value to binary coded decimal.
:param value: the binary value to convert to BCD. (required, no default)
"""
return value + 6 * (value // 10)
ALARM_COMPONENT_DISABLED = 0x80
FREQUENCY = ["secondly", "minutely", "hourly", "daily", "weekly", "monthly"]
[docs]class BCDAlarmTimeRegister:
"""
Alarm date and time register using binary coded decimal structure.
The byte order of the registers must* be: [second], minute, hour, day,
weekday. Each byte must also have a high enable bit where 1 is disabled and
0 is enabled.
* If weekday_shared is True, then weekday and day share a register.
* If has_seconds is True, then there is a seconds register.
Values are a tuple of (`time.struct_time`, `str`) where the struct represents
a date and time that would alarm. The string is the frequency:
* "secondly", once a second (only if alarm has_seconds)
* "minutely", once a minute when seconds match (if alarm doesn't seconds then when seconds = 0)
* "hourly", once an hour when ``tm_min`` and ``tm_sec`` match
* "daily", once a day when ``tm_hour``, ``tm_min`` and ``tm_sec`` match
* "weekly", once a week when ``tm_wday``, ``tm_hour``, ``tm_min``, ``tm_sec`` match
* "monthly", once a month when ``tm_mday``, ``tm_hour``, ``tm_min``, ``tm_sec`` match
:param int register_address: The register address to start the read
:param bool has_seconds: True if the alarm can happen minutely.
:param bool weekday_shared: True if weekday and day share the same register
:param int weekday_start: 0 or 1 depending on the RTC's representation of the first day of the
week (Monday)
"""
# Defaults are based on alarm1 of the DS3231.
def __init__(self, register_address, has_seconds=True, weekday_shared=True, weekday_start=1):
buffer_size = 5
if weekday_shared:
buffer_size -= 1
if has_seconds:
buffer_size += 1
self.has_seconds = has_seconds
self.buffer = bytearray(buffer_size)
self.buffer[0] = register_address
self.weekday_shared = weekday_shared
self.weekday_start = weekday_start
def __get__(self, obj, objtype=None):
# Read the alarm register.
with obj.i2c_device:
obj.i2c_device.write(self.buffer, end=1, stop=False)
obj.i2c_device.readinto(self.buffer, start=1)
frequency = None
i = 1
seconds = 0
if self.has_seconds:
if (self.buffer[1] & 0x80) != 0:
frequency = "secondly"
else:
frequency = "minutely"
seconds = _bcd2bin(self.buffer[1] & 0x7f)
i = 2
minute = 0
if (self.buffer[i] & 0x80) == 0:
frequency = "hourly"
minute = _bcd2bin(self.buffer[i] & 0x7f)
hour = 0
if (self.buffer[i + 1] & 0x80) == 0:
frequency = "daily"
hour = _bcd2bin(self.buffer[i + 1] & 0x7f)
mday = None
wday = None
if (self.buffer[i + 2] & 0x80) == 0:
# day of the month
if not self.weekday_shared or (self.buffer[i + 2] & 0x40) == 0:
frequency = "monthly"
mday = _bcd2bin(self.buffer[i + 2] & 0x3f)
else: # weekday
frequency = "weekly"
wday = _bcd2bin(self.buffer[i + 2] & 0x3f) - self.weekday_start
# weekday
if not self.weekday_shared and (self.buffer[i + 3] & 0x80) == 0:
frequency = "monthly"
mday = _bcd2bin(self.buffer[i + 3] & 0x7f)
if mday is not None:
wday = (mday - 2) % 7
elif wday is not None:
mday = wday + 2
else:
# Jan 1, 2017 was a Sunday (6)
wday = 6
mday = 1
return (time.struct_time((2017, 1, mday, hour, minute, seconds, wday, mday, -1)), frequency)
def __set__(self, obj, value):
if len(value) != 2:
raise ValueError("Value must be sequence of length two")
# Turn all components off by default.
for i in range(len(self.buffer) - 1):
self.buffer[i + 1] = ALARM_COMPONENT_DISABLED
frequency_name = value[1]
error_message = "%s is not a supported frequency" % frequency_name
if frequency_name not in FREQUENCY:
raise ValueError(error_message)
frequency = FREQUENCY.index(frequency_name)
if frequency <= 1 and not self.has_seconds:
raise ValueError(error_message)
# i is the index of the minute byte
i = 2 if self.has_seconds else 1
if frequency > 0 and self.has_seconds: # minutely at least
self.buffer[1] = _bin2bcd(value[0].tm_sec)
if frequency > 1: # hourly at least
self.buffer[i] = _bin2bcd(value[0].tm_min)
if frequency > 2: # daily at least
self.buffer[i + 1] = _bin2bcd(value[0].tm_hour)
if value[1] == "weekly":
if self.weekday_shared:
self.buffer[i + 2] = _bin2bcd(value[0].tm_wday + self.weekday_start) | 0x40
else:
self.buffer[i + 3] = _bin2bcd(value[0].tm_wday + self.weekday_start)
elif value[1] == "monthly":
self.buffer[i + 2] = _bin2bcd(value[0].tm_mday)
with obj.i2c_device:
obj.i2c_device.write(self.buffer)