25 lines
645 B
Python
25 lines
645 B
Python
import serial
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import wiringpi
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import array
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import fcntl
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import termios
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DE_PIN = 0
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class MyRS485(serial.Serial):
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def __init__(self, *args, **kwargs):
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super().__init__(*args, **kwargs)
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wiringpi.wiringPiSetup()
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wiringpi.pinMode(DE_PIN, wiringpi.OUTPUT)
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self.buf = array.array('h', [0])
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def write(self, b):
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wiringpi.digitalWrite(DE_PIN, wiringpi.HIGH)
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super().write(b)
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while True:
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fcntl.ioctl(self.fileno(), termios.TIOCSERGETLSR, self.buf, 1)
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if self.buf[0] & termios.TIOCSER_TEMT:
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break
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wiringpi.digitalWrite(DE_PIN, wiringpi.LOW)
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