ds1338 driver for micropython

ds1338.py

import utime as time
import umachine as machine
import ubinascii as binascii

ds1338_address = 0b1101000

def _bcd_to_int(bcd):
    out = 0
    for d in (bcd >> 4, bcd):
        for p in (1, 2, 4 ,8):
            if d & 1:
                out += p
            d >>= 1
        out *= 10
    return out // 10


def _int_to_bcd(n):
    bcd = 0
    for i in (n // 10, n % 10):
        for p in (8, 4, 2, 1):
            if i >= p:
                bcd += 1
                i -= p
            bcd <<= 1
    return bcd >> 1


class DS1338Drv:
  def __init__(self, i2c):
    if type(i2c) is not machine.I2C:
      raise ValueError("Not a valid I2C type")
    self.i2c = i2c
    self.reg_map = bytearray(8)
    
  def getRegMap(self):
    return self.i2c.mem_read(self.reg_map, ds1338_address, 0x00)
  
  def getCurrentTime(self):
    ret = self.getRegMap()
    second = _bcd_to_int(ret[0])
    minute = _bcd_to_int(ret[1])
    hour = _bcd_to_int(ret[2])
    day = _bcd_to_int(ret[3])
    date = _bcd_to_int(ret[4])
    month = _bcd_to_int(ret[5])
    year = 2000 + _bcd_to_int(ret[6])
    return (second, minute, hour, day, date, month, year)
  
  def setCurrentTime(self, datetime):
    second = _int_to_bcd(datetime[0])
    minute = _int_to_bcd(datetime[1])
    hour = _int_to_bcd(datetime[2])
    day = _int_to_bcd(datetime[3])
    date = _int_to_bcd(datetime[4])
    month = _int_to_bcd(datetime[5])
    year = _bcd_to_int(datetime[6] - 2000)
    
    l = [second, minute, hour, day, date, month, year]
    b = bytearray(l)
    self.i2c.mem_write(b, ds1338_address, 0x00)