52 lines
1.7 KiB
Python
52 lines
1.7 KiB
Python
import RPi.GPIO as GPIO
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from time import sleep
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class ShiftRegister:
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def __init__(self, data_pin, latch_pin, clock_pin):
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self.data_pin = data_pin
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self.latch_pin = latch_pin
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self.clock_pin = clock_pin
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self.current_byte = 0 # Tracks the current state of the shift register
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GPIO.setmode(GPIO.BCM)
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GPIO.setup(self.data_pin, GPIO.OUT)
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GPIO.setup(self.latch_pin, GPIO.OUT)
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GPIO.setup(self.clock_pin, GPIO.OUT)
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def write_byte(self, byte):
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"""Writes an 8-bit value to the shift register."""
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GPIO.output(self.latch_pin, 0)
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for i in range(8):
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GPIO.output(self.clock_pin, 0)
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GPIO.output(self.data_pin, (byte >> (7 - i)) & 1) # MSB first
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GPIO.output(self.clock_pin, 1)
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GPIO.output(self.latch_pin, 1)
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self.current_byte = byte # Update the internal state
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def clear(self):
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"""Clears the shift register (sets all outputs to 0)."""
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self.write_byte(0)
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def set_pin(self, pin, state):
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"""
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Sets an individual pin to HIGH (1) or LOW (0).
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Pins are numbered 0-7, with 0 being the LSB (Q0) and 7 being the MSB (Q7).
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"""
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if not 0 <= pin <= 7:
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raise ValueError("Pin must be in range 0-7.")
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if state:
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self.current_byte |= (1 << pin) # Set the bit to 1
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else:
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self.current_byte &= ~(1 << pin) # Set the bit to 0
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self.write_byte(self.current_byte)
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def toggle_pin(self, pin):
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"""Toggles the state of an individual pin."""
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if not 0 <= pin <= 7:
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raise ValueError("Pin must be in range 0-7.")
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self.current_byte ^= (1 << pin) # Flip the bit
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self.write_byte(self.current_byte)
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