如何用ili9341显示屏显示时钟表盘

要在ili9341显示屏上显示时钟表盘，你需要使用一些基本的图形库和时钟库来绘制表盘和时针、分针和秒针。

以下是一些基本的步骤：

1. 初始化ili9341显示屏，并设置显示屏分辨率为240x320

2. 创建一个时钟库并初始化时间

3. 使用图形库绘制表盘的外圆和刻度线

4. 根据时间计算时针、分针和秒针的位置和角度

5. 使用图形库绘制时针、分针和秒针

6. 刷新显示屏

下面是一个基本的示例代码：

import time
import math
import Adafruit_ILI9341 as ili9341
import Adafruit_GPIO.SPI as SPI

# 初始化SPI接口
SPI_PORT = 0
SPI_DEVICE = 0
spi = SPI.SpiDev(SPI_PORT, SPI_DEVICE)

# 初始化显示屏
disp = ili9341.ILI9341(dc=18, spi=spi, rst=23, cs=25, backlight=24, rotation=90)

# 设置表盘参数
CENTER_X = 120
CENTER_Y = 160
RADIUS = 120

# 绘制表盘
def draw_clock_face():
    # 绘制外圆
    disp.draw_circle(CENTER_X, CENTER_Y, RADIUS, ili9341.WHITE)
    # 绘制刻度线
    for i in range(60):
        angle = math.radians(i * 6)
        x1 = int(math.cos(angle) * (RADIUS - 10) + CENTER_X)
        y1 = int(math.sin(angle) * (RADIUS - 10) + CENTER_Y)
        x2 = int(math.cos(angle) * (RADIUS - 20) + CENTER_X)
        y2 = int(math.sin(angle) * (RADIUS - 20) + CENTER_Y)
        disp.draw_line(x1, y1, x2, y2, ili9341.WHITE)

# 绘制时针、分针和秒针
def draw_hands(hour, minute, second):
    # 绘制时针
    hour_angle = math.radians((hour % 12) * 30 + minute / 2)
    hour_x = int(math.cos(hour_angle) * (RADIUS - 60) + CENTER_X)
    hour_y = int(math.sin(hour_angle) * (RADIUS - 60) + CENTER_Y)
    disp.draw_line(CENTER_X, CENTER_Y, hour_x, hour_y, ili9341.RED, 5)
    # 绘制分针
    minute_angle = math.radians(minute * 6)
    minute_x = int(math.cos(minute_angle) * (RADIUS - 40) + CENTER_X)
    minute_y = int(math.sin(minute_angle) * (RADIUS - 40) + CENTER_Y)
    disp.draw_line(CENTER_X, CENTER_Y, minute_x, minute_y, ili9341.BLUE, 3)
    # 绘制秒针
    second_angle = math.radians(second * 6)
    second_x = int(math.cos(second_angle) * (RADIUS - 20) + CENTER_X)
    second_y = int(math.sin(second_angle) * (RADIUS - 20) + CENTER_Y)
    disp.draw_line(CENTER_X, CENTER_Y, second_x, second_y, ili9341.GREEN, 1)

# 主循环
while True:
    # 获取当前时间
    now = time.localtime()
    hour = now.tm_hour
    minute = now.tm_min
    second = now.tm_sec
    # 清空显示屏
    disp.clear()
    # 绘制表盘
    draw_clock_face()
    # 绘制时针、分针和秒针
    draw_hands(hour, minute, second)
    # 刷新显示屏
    disp.display()
    # 等待1秒
    time.sleep(1)

这只是一个基本的示例，你可以根据自己的需求进行修改和扩展。