"""
TM1637 for Four Digit LED Display

Micropython library for the TM1637
=======================================================
@dahanzimin From the Mixly Team 
"""
from machine import Pin
from time import sleep_us
from micropython import const

TM1637_CMD1 	= const(0x40)
TM1637_CMD2 	= const(0xC0)
TM1637_CMD3 	= const(0x80)
TM1637_DSP_ON 	= const(0x08)
TM1637_DELAY 	= const(0x0A)
_SEGMENTS		= b'\x3F\x06\x5B\x4F\x66\x6D\x7D\x07\x7F\x6F\x77\x7C\x39\x5E\x79\x71'

class TM1637:
	def __init__(self, clk, dio, brightness=2):
		self.clk = Pin(clk, Pin.OUT, value=0)
		self.dio = Pin(dio, Pin.OUT, value=0)
		sleep_us(TM1637_DELAY)
		self._intensity = brightness
		self.dbuf = [0, 0, 0, 0]
		self.on()

	def _start(self):
		self.dio(0)
		sleep_us(TM1637_DELAY)
		self.clk(0)
		sleep_us(TM1637_DELAY)

	def _stop(self):
		self.dio(0)
		sleep_us(TM1637_DELAY)
		self.clk(1)
		sleep_us(TM1637_DELAY)
		self.dio(1)

	def _write(self, b):
		for i in range(8):
			self.dio((b >> i) & 1)
			sleep_us(TM1637_DELAY)
			self.clk(1)
			sleep_us(TM1637_DELAY)
			self.clk(0)
			sleep_us(TM1637_DELAY)
		self.clk(0)
		sleep_us(TM1637_DELAY)
		self.clk(1)
		sleep_us(TM1637_DELAY)
		self.clk(0)
		sleep_us(TM1637_DELAY)

	def intensity(self, val=None):
		"""Set the display brightness 0-7."""
		if val is None:
			return self._intensity
		val = max(min(val, 7), 0)
		self._intensity = val
		if val == 0:
			self.off()
		else:
			self.on()

	def on(self):
		self._start()
		self._write(TM1637_CMD1)
		self._stop()
		self._start()
		self._write(TM1637_CMD3 | TM1637_DSP_ON | self._intensity)
		self._stop()

	def off(self):
		self._start()
		self._write(TM1637_CMD3)
		self._stop()

	def dat(self, bit, data):
		self._start()
		self._write(TM1637_CMD2 | bit)
		self._write(data)
		self._stop()

	def clear(self):
		self.dat(0, 0)
		self.dat(1, 0)
		self.dat(2, 0)
		self.dat(3, 0)
		self.dbuf = [0, 0, 0, 0]

	def showbit(self, num, bit=0):
		self.dbuf[bit % 4] = _SEGMENTS[num % 16]
		self.dat(bit, _SEGMENTS[num % 16])

	def shownum(self, num):
		if num < 0:
			self.dat(0, 0x40)   # '-'
			num = -num
		else:
			self.showbit((num // 1000) % 10)
		self.showbit(num % 10, 3)
		self.showbit((num // 10) % 10, 2)
		self.showbit((num // 100) % 10, 1)

	def showhex(self, num):
		if num < 0:
			self.dat(0, 0x40)   # '-'
			num = -num
		else:
			self.showbit((num >> 12) % 16)
		self.showbit(num % 16, 3)
		self.showbit((num >> 4) % 16, 2)
		self.showbit((num >> 8) % 16, 1)

	def showDP(self, bit=1, show=True):
		if show:
			self.dat(bit, self.dbuf[bit] | 0x80)
		else:
			self.dat(bit, self.dbuf[bit] & 0x7F)