FourDigitDisplay.py

'''
    microbit drive for Four Digit LED Display (TM1650)

    Author: shaoziyang
    Date:   2018.3

    http://www.micropython.org.cn
'''
from microbit import *

COMMAND_I2C_ADDRESS = 0x24
DISPLAY_I2C_ADDRESS = 0x34

buf = (0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07,0x7F,0x6F,0x77,0x7C,0x39,0x5E,0x79,0x71)

class FourDigitDisplay():
    def __init__(self):
        self._intensity = 3
        self.dbuf = [0, 0, 0, 0]
        self.tbuf = bytearray(1)
        self.on()

    def intensity(self, dat = -1):
        if dat < 0 or dat > 8:
            return self._intensity
        if dat == 0:
            self.off()
        else:
            self._intensity = dat
            self.cmd((dat<<4)|0x01)

    def cmd(self, c):
        self.tbuf[0] = c
        i2c.write(COMMAND_I2C_ADDRESS, self.tbuf)

    def dat(self, bit, d):
        self.tbuf[0] = d
        i2c.write(DISPLAY_I2C_ADDRESS + (bit%4), self.tbuf)

    def on(self):
        self.cmd((self._intensity<<4)|0x01)

    def off(self):
        self._intensity = 0
        self.cmd(0)

    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] = buf[num%16]
        self.dat(bit, buf[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)