python_microcontrollers/04_output/code/my74HC595.py at main · ColinKerr/python_microcontrollers · GitHub

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from machine import Pin

# 74HC595
# 16: VCC
# 15, 1~7: Q0~Q7
# 14: DS
# 13: OE
# 12: STCP
# 11: SHCP
# 9: Q7S
# 8: GND

class Chip74HC595(object):
    def __init__(self, ds: int=12, stcp: int=13, shcp: int=14, oe: int=5):
        self._ds = Pin(ds, Pin.OUT, value=0)
        self._shcp = Pin(shcp, Pin.OUT, value=0)
        self._stcp = Pin(stcp, Pin.OUT, value=0)
        if oe==-1:
            self._oe = -1
        else:
            self._oe = Pin(oe, Pin.OUT, value=0)
        self.enable()

    def shiftOut(self,direction,data):
        self._shcp.on()
        self._stcp.on()
        if direction:
            for i in range(8):
                bit=data<<i
                bit=bit&0x80
                if bit==0x80:
                    self._ds.on()
                else:
                    self._ds.off()
                self._shift_bit()
            self._send_data()
        if not direction:
            for i in range(8):
                bit=data>>i
                bit=bit&0x01
                if bit==0x01:
                    self._ds.on()
                else:
                    self._ds.off()
                self._shift_bit()
            self._send_data()

    def clear(self):
        for i in range(8):
            self._ds.off()
            self._shift_bit()
        self._send_data()
        self.enable()

    def _shift_bit(self):
        self._shcp.off()
        self._shcp.on()

    def _send_data(self):
        self._stcp.off()
        self._stcp.on()

    def disable(self):
        if self._oe != -1:
            self._oe.on()

    def enable(self):
        if self._oe != -1:
            self._oe.off()