# 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__ = "1.3.1" __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"] 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)