Adolfo Reyna
133 lines
4.3 KiB
Python
133 lines
4.3 KiB
Python
"""CircuitPython PCF85063 Real-Time Clock (RTC) driver.
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Synchronizes the hardware RTC with CircuitPython's native rtc.RTC() system clock.
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"""
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import rtc
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import time
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class PCF85063:
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ADDR = 0x51
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TIME_REG_START = 0x04
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def __init__(self, i2c):
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self.i2c = i2c
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self._init_rtc()
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def read_reg(self, reg, n=1):
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while not self.i2c.try_lock():
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pass
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try:
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self.i2c.writeto(self.ADDR, bytes([reg]))
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buf = bytearray(n)
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self.i2c.readfrom_into(self.ADDR, buf)
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return buf
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except Exception as e:
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print(f"RTC read failed at reg 0x{reg:02X}: {e}")
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return None
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finally:
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self.i2c.unlock()
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def write_reg(self, reg, data):
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while not self.i2c.try_lock():
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pass
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try:
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payload = bytearray([reg])
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if isinstance(data, (bytes, bytearray, list)):
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payload.extend(data)
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else:
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payload.append(data)
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self.i2c.writeto(self.ADDR, payload)
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return True
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except Exception as e:
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print(f"RTC write failed at reg 0x{reg:02X}: {e}")
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return False
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finally:
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self.i2c.unlock()
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def _init_rtc(self):
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ctrl1 = self.read_reg(0x00, 1)
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if ctrl1 is not None and (ctrl1[0] & 0x20):
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print("RTC oscillator was stopped. Starting oscillator...")
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self.write_reg(0x00, 0x00)
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def _dec2bcd(self, val):
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return (val // 10 << 4) | (val % 10)
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def _bcd2dec(self, val):
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return ((val >> 4) * 10) + (val & 0x0F)
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def get_datetime(self):
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"""Reads current time from hardware RTC.
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Returns:
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tuple: (year, month, day, weekday, hour, minute, second) or None on error.
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"""
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data = self.read_reg(self.TIME_REG_START, 7)
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if data is None:
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return None
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second = self._bcd2dec(data[0] & 0x7F)
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minute = self._bcd2dec(data[1] & 0x7F)
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hour = self._bcd2dec(data[2] & 0x3F)
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day = self._bcd2dec(data[3] & 0x3F)
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weekday = data[4] & 0x07
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month = self._bcd2dec(data[5] & 0x1F)
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year = 2000 + self._bcd2dec(data[6])
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return (year, month, day, weekday, hour, minute, second)
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def set_datetime(self, dt):
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"""Sets the hardware RTC time.
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Args:
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dt (tuple): (year, month, day, weekday, hour, minute, second)
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"""
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try:
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year, month, day, weekday, hour, minute, second = dt
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reg_year = year % 100
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data = bytearray(7)
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data[0] = self._dec2bcd(second) & 0x7F
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data[1] = self._dec2bcd(minute)
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data[2] = self._dec2bcd(hour)
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data[3] = self._dec2bcd(day)
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data[4] = weekday & 0x07
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data[5] = self._dec2bcd(month)
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data[6] = self._dec2bcd(reg_year)
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return self.write_reg(self.TIME_REG_START, data)
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except Exception as e:
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print(f"Error setting PCF85063 RTC: {e}")
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return False
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def sync_to_system(self):
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"""Synchronizes the CircuitPython system time from the hardware RTC."""
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dt = self.get_datetime()
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if dt:
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year, month, day, weekday, hour, minute, second = dt
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r = rtc.RTC()
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r.datetime = time.struct_time((year, month, day, hour, minute, second, weekday, -1, -1))
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print(f"System clock synced to RTC: {year:04d}-{month:02d}-{day:02d} {hour:02d}:{minute:02d}:{second:02d}")
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return True
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return False
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def sync_from_system(self):
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"""Synchronizes the hardware RTC time from the system clock."""
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try:
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t = time.localtime()
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dt = (t.tm_year, t.tm_mon, t.tm_mday, t.tm_wday, t.tm_hour, t.tm_min, t.tm_sec)
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success = self.set_datetime(dt)
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if success:
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print(f"RTC synced from System: {t.tm_year:04d}-{t.tm_mon:02d}-{t.tm_mday:02d} {t.tm_hour:02d}:{t.tm_min:02d}:{t.tm_sec:02d}")
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return success
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except Exception as e:
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print(f"Error syncing RTC from system: {e}")
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return False
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def get_time_string(self):
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dt = self.get_datetime()
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if dt:
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return f"{dt[0]:04d}-{dt[1]:02d}-{dt[2]:02d} {dt[4]:02d}:{dt[5]:02d}:{dt[6]:02d}"
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return "0000-00-00 00:00:00"
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