raspberry-pi3 - 如何更改 2x16 LCD 显示器的背光颜色

问题描述

我正在使用带有 Raspberry Pi 3 的 2x16 LCD 显示器和 16 个接头引脚。为了显示我安装并配置了 Adafruit Char LCD 库的消息。它工作正常。

目前默认背光颜色为黄色，所以我想将其更改为其他颜色，如蓝色、红色。为此，我从 Adafruit char LCD 库中导入的Adafruit_RGBCharLCD 类Adafruit_RGBCharLCD如下

class Adafruit_RGBCharLCD(Adafruit_CharLCD):
    """Class to represent and interact with an HD44780 character LCD display with
    an RGB backlight."""

    def __init__(self, rs, en, d4, d5, d6, d7, cols, lines, red, green, blue,
                 gpio=GPIO.get_platform_gpio(), 
                 invert_polarity=True,
                 enable_pwm=False,
                 pwm=PWM.get_platform_pwm(),
                 initial_color=(1.0, 1.0, 1.0)):
        """Initialize the LCD with RGB backlight.  RS, EN, and D4...D7 parameters 
        should be the pins connected to the LCD RS, clock enable, and data line 
        4 through 7 connections. The LCD will be used in its 4-bit mode so these 
        6 lines are the only ones required to use the LCD.  You must also pass in
        the number of columns and lines on the LCD.

        The red, green, and blue parameters define the pins which are connected
        to the appropriate backlight LEDs.  The invert_polarity parameter is a
        boolean that controls if the LEDs are on with a LOW or HIGH signal.  By
        default invert_polarity is True, i.e. the backlight LEDs are on with a
        low signal.  If you want to enable PWM on the backlight LEDs (for finer
        control of colors) and the hardware supports PWM on the provided pins,
        set enable_pwm to True.  Finally you can set an explicit initial backlight
        color with the initial_color parameter.  The default initial color is
        white (all LEDs lit).

        You can optionally pass in an explicit GPIO class,
        for example if you want to use an MCP230xx GPIO extender.  If you don't
        pass in an GPIO instance, the default GPIO for the running platform will
        be used.
        """
        super(Adafruit_RGBCharLCD, self).__init__(rs, en, d4, d5, d6, d7,
                                                  cols,
                                                  lines, 
                                                  enable_pwm=enable_pwm,
                                                  backlight=None,
                                                  invert_polarity=invert_polarity,
                                                  gpio=gpio, 
                                                  pwm=pwm)
        self._red = red
        self._green = green
        self._blue = blue
        # Setup backlight pins.
        if enable_pwm:
            # Determine initial backlight duty cycles.
            rdc, gdc, bdc = self._rgb_to_duty_cycle(initial_color)
            pwm.start(red, rdc)
            pwm.start(green, gdc)
            pwm.start(blue, bdc)
        else:
            gpio.setup(red, GPIO.OUT)
            gpio.setup(green, GPIO.OUT)
            gpio.setup(blue, GPIO.OUT)
            self._gpio.output_pins(self._rgb_to_pins(initial_color))

    def _rgb_to_duty_cycle(self, rgb):
        # Convert tuple of RGB 0-1 values to tuple of duty cycles (0-100).
        red, green, blue = rgb
        # Clamp colors between 0.0 and 1.0
        red = max(0.0, min(1.0, red))
        green = max(0.0, min(1.0, green))
        blue = max(0.0, min(1.0, blue))
        return (self._pwm_duty_cycle(red), 
                self._pwm_duty_cycle(green),
                self._pwm_duty_cycle(blue))

    def _rgb_to_pins(self, rgb):
        # Convert tuple of RGB 0-1 values to dict of pin values.
        red, green, blue = rgb
        return { self._red:   self._blpol if red else not self._blpol,
                 self._green: self._blpol if green else not self._blpol,
                 self._blue:  self._blpol if blue else not self._blpol }

    def set_color(self, red, green, blue):
        """Set backlight color to provided red, green, and blue values.  If PWM
        is enabled then color components can be values from 0.0 to 1.0, otherwise
        components should be zero for off and non-zero for on.
        """
        if self._pwm_enabled:
            # Set duty cycle of PWM pins.
            rdc, gdc, bdc = self._rgb_to_duty_cycle((red, green, blue))
            self._pwm.set_duty_cycle(self._red, rdc)
            self._pwm.set_duty_cycle(self._green, gdc)
            self._pwm.set_duty_cycle(self._blue, bdc)
        else:
            # Set appropriate backlight pins based on polarity and enabled colors.
            self._gpio.output_pins({self._red:   self._blpol if red else not self._blpol,
                                    self._green: self._blpol if green else not self._blpol,
                                    self._blue:  self._blpol if blue else not self._blpol })

    def set_backlight(self, backlight):
        """Enable or disable the backlight.  If PWM is not enabled (default), a
        non-zero backlight value will turn on the backlight and a zero value will
        turn it off.  If PWM is enabled, backlight can be any value from 0.0 to
        1.0, with 1.0 being full intensity backlight.  On an RGB display this
        function will set the backlight to all white.
        """
        self.set_color(backlight, backlight, backlight)

我正在尝试lcd.set_color() 按如下方式使用，但它不起作用。

import time
from Adafruit_CharLCD import Adafruit_RGBCharLCD

# instantiate lcd and specify pins
lcd = Adafruit_RGBCharLCD(rs=26, en=19,
                       d4=13, d5=6, d6=5, d7=11,
                       cols=16, lines=2,red=True,Green=True,Blue=True)
lcd.clear()
#setting backlight color as blue
lcd.set_color(0,0,100)


# display text on LCD display \n = new line
lcd.message('2x16 CharLCD\n  Raspberry Pi')

我正在使用 4 位节点，将最后两个作为背光引脚的引脚连接到树莓派 gpio 引脚，如下所示：

背光引脚

  15     LED+ or A        Pin No 2 of GPIO(5v Power)
  16      LED- or K       Pin No 6 of GPIO(GND)

请帮我将自定义颜色设置为背光，因为我对这一切都不熟悉。

标签： raspberry-pi3lcdadafruitbacklight

raspberry-pi3 - 如何更改 2x16 LCD 显示器的背光颜色

问题描述

解决方案

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