Raspberry Pi Pico W连接Waveshare 1.3寸LCD无法显示文本求助
2026-6-30
问题描述
使用2022款Raspberry Pi Pico W，背部连接1.3寸Waveshare Pico LCD显示屏，屏幕亮度可调、按键功能正常，但无法显示任何文本。相关代码如下：
显示屏驱动代码
from machine import Pin,SPI,PWM import framebuf import utime import os import math # ============ Start of Drive Code ================ BL = 13 # 显示屏使用的引脚 DC = 8 RST = 12 MOSI = 11 SCK = 10 CS = 9 class LCD_1inch3(framebuf.FrameBuffer): def __init__(self): self.width = 240 self.height = 240 self.cs = Pin(CS,Pin.OUT) self.rst = Pin(RST,Pin.OUT) self.cs(1) self.spi = SPI(1) self.spi = SPI(1,1000_000) self.spi = SPI(1,100000_000,polarity=0, phase=0,sck=Pin(SCK),mosi=Pin(MOSI),miso=None) self.dc = Pin(DC,Pin.OUT) self.dc(1) self.buffer = bytearray(self.height * self.width * 2) super().__init__(self.buffer, self.width, self.height, framebuf.RGB565) self.init_display() self.red = 0x07E0 # 预定义颜色 self.green = 0x001f # 建议使用下方定义的colour(r,g,b)函数 self.blue = 0xf800 self.white = 0xffff def write_cmd(self, cmd): self.cs(1) self.dc(0) self.cs(0) self.spi.write(bytearray([cmd])) self.cs(1) def write_data(self, buf): self.cs(1) self.dc(1) self.cs(0) self.spi.write(bytearray([buf])) self.cs(1) def init_display(self): """初始化显示屏""" self.rst(1) self.rst(0) self.rst(1) self.write_cmd(0x36) self.write_data(0x70) self.write_cmd(0x3A) self.write_data(0x05) self.write_cmd(0xB2) self.write_data(0x0C) self.write_data(0x0C) self.write_data(0x00) self.write_data(0x33) self.write_data(0x33) self.write_cmd(0xB7) self.write_data(0x35) self.write_cmd(0xBB) self.write_data(0x19) self.write_cmd(0xC0) self.write_data(0x2C) self.write_cmd(0xC2) self.write_data(0x01) self.write_cmd(0xC3) self.write_data(0x12) self.write_cmd(0xC4) self.write_data(0x20) self.write_cmd(0xC6) self.write_data(0x0F) self.write_cmd(0xD0) self.write_data(0xA4) self.write_data(0xA1) self.write_cmd(0xE0) self.write_data(0xD0) self.write_data(0x04) self.write_data(0x0D) self.write_data(0x11) self.write_data(0x13) self.write_data(0x2B) self.write_data(0x3F) self.write_data(0x54) self.write_data(0x4C) self.write_data(0x18) self.write_data(0x0D) self.write_data(0x0B) self.write_data(0x1F) self.write_data(0x23) self.write_cmd(0xE1) self.write_data(0xD0) self.write_data(0x04) self.write_data(0x0C) self.write_data(0x11) self.write_data(0x13) self.write_data(0x2C) self.write_data(0x3F) self.write_data(0x44) self.write_data(0x51) self.write_data(0x2F) self.write_data(0x1F) self.write_data(0x1F) self.write_data(0x20) self.write_data(0x23) self.write_cmd(0x21) self.write_cmd(0x11) self.write_cmd(0x29) def show(self): self.write_cmd(0x2A) self.write_data(0x00) self.write_data(0x00) self.write_data(0x00) self.write_data(0xef) self.write_cmd(0x2B) self.write_data(0x00) self.write_data(0x00) self.write_data(0x00) self.write_data(0xEF) self.write_cmd(0x2C) self.cs(1) self.dc(1) self.cs(0) self.spi.write(self.buffer, buf_len=self.width*self.height*2) self.cs(1) # ========= End of Driver =========== def colour(R,G,B): # 获取红色值 rp = int(R*31/255) # 范围0-31 if rp < 0: rp = 0 r = rp *8 # 获取绿色值 - 稍复杂 gp = int(G*63/255) # 范围0-63 if gp < 0: gp = 0 g = 0 if gp & 1: g = g + 8192 if gp & 2: g = g + 16384 if gp & 4: g = g + 32768 if gp & 8: g = g + 1 if gp & 16: g = g + 2 if gp & 32: g = g + 4 # 获取蓝色值 bp =int(B*31/255) # 范围0-31 if bp < 0: bp = 0 b = bp *256 colour = r+g+b return colour
主程序代码
pwm = PWM(Pin(BL)) # Screen Brightness pwm.freq(1000) pwm.duty_u16(65534) # max 65535 - mid value LCD = LCD_1inch3() while True: # Background colour - dark grey LCD.fill(colour(0,0,0)) # Define pins for buttons and Joystick keyA = Pin(15,Pin.IN,Pin.PULL_UP) # Normally 1 but 0 if pressed keyB = Pin(17,Pin.IN,Pin.PULL_UP) keyX = Pin(19,Pin.IN,Pin.PULL_UP) keyY= Pin(21,Pin.IN,Pin.PULL_UP) up = Pin(2,Pin.IN,Pin.PULL_UP) down = Pin(18,Pin.IN,Pin.PULL_UP) left = Pin(16,Pin.IN,Pin.PULL_UP) right = Pin(20,Pin.IN,Pin.PULL_UP) ctrl = Pin(3,Pin.IN,Pin.PULL_UP) LCD.text('Hi', 120, 120, colour(255, 255, 255))
问题解决
核心问题
主程序中从未调用LCD.show()方法，所有绘制操作（fill、text）都只修改了内存中的帧缓冲区，没有将内容同步到物理屏幕上，这是屏幕无显示的直接原因。
额外优化点
- 按键引脚初始化重复：原代码在循环内每次都重新初始化按键引脚，属于无效操作，应移到循环外执行一次。
- SPI初始化冗余：驱动中SPI被重复赋值三次，可简化为一行代码。
修改后的主程序代码
pwm = PWM(Pin(BL)) # 屏幕亮度控制 pwm.freq(1000) pwm.duty_u16(65534) # 最大值为65535，此处设为接近最大值 LCD = LCD_1inch3() # 按键和摇杆引脚定义移至循环外，避免重复初始化 keyA = Pin(15, Pin.IN, Pin.PULL_UP) # 默认高电平，按下时为低电平 keyB = Pin(17, Pin.IN, Pin.PULL_UP) keyX = Pin(19, Pin.IN, Pin.PULL_UP) keyY = Pin(21, Pin.IN, Pin.PULL_UP) up = Pin(2, Pin.IN, Pin.PULL_UP) down = Pin(18, Pin.IN, Pin.PULL_UP) left = Pin(16, Pin.IN, Pin.PULL_UP) right = Pin(20, Pin.IN, Pin.PULL_UP) ctrl = Pin(3, Pin.IN, Pin.PULL_UP) while True: # 填充背景为黑色 LCD.fill(colour(0, 0, 0)) # 在屏幕中央绘制白色文本 LCD.text('Hi', 120, 120, colour(255, 255, 255)) # 关键：调用show()将缓冲区内容刷新到屏幕 LCD.show()
可选：简化驱动中的SPI初始化
将驱动中三次SPI赋值替换为一行：
self.spi = SPI(1, baudrate=100000000, polarity=0, phase=0, sck=Pin(SCK), mosi=Pin(MOSI), miso=None)
内容的提问来源于stack exchange，提问作者Minion123
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