display.py 文件源码

def setup(self):
        """ setup GPIO pins and start GPIO PWM
        """
        from RPLCD import CharLCD
        from RPi import GPIO as GPIO

        GPIO.setup(self.pin_contrast, GPIO.OUT)
        self.lcd = CharLCD(pin_rs=self.pin_rs, pin_rw=self.pin_rw, pin_e=self.pin_e, pins_data=self.pins_data,
                           numbering_mode=GPIO.BOARD, cols=Display.COLUMNS, rows=Display.ROWS, dotsize=8)
        self.lcd.cursor_pos = (0, 0)

        # the contrast needs a curtain  current, found value by try and error
        self.contrast = GPIO.PWM(self.pin_contrast, 1000)
        self.contrast.start(40)