树莓派小车led亮度随超声波测距的距离而改变的代码

在树莓派上制作一个小车LED灯随超声波传感器测距变暗的简单代码示例通常会用到Python编程语言和GPIO模块。这里我们假设你已经安装了`RPi.GPIO`库。首先，你需要设置GPIO，连接超声波传感器和LED灯。

import RPi.GPIO as GPIO
import time

# 设置GPIO模式
GPIO.setmode(GPIO.BCM)

# 定义超声波传感器和LED的GPIO pin
ultrasonic_trig = 23
ultrasonic_echo = 24
led_pin = 17

# 初始化GPIO
GPIO.setup(ultrasonic_trig, GPIO.OUT)
GPIO.setup(ultrasonic_echo, GPIO.IN)
GPIO.setup(led_pin, GPIO.OUT)

def measure_distance():
    GPIO.output(ultrasonic_trig, False)
    time.sleep(0.00001)  # 发射脉冲
    GPIO.output(ultrasonic_trig, True)
    time.sleep(0.00005)  # 脉冲持续时间
    GPIO.output(ultrasonic_trig, False)
    
    start_time = time.time()
    while GPIO.input(ultrasonic_echo) == 0:
        pass
    received_time = time.time()

    distance = (received_time - start_time) * 343 / 2  # 使用公式计算距离（单位：厘米）
    return distance

def adjust_led_brightness(distance):
    brightness = int(distance * 100) / 100  # 距离越大，亮度越低
    GPIO.output(led_pin, GPIO.HIGH if brightness > 0 else GPIO.LOW)  # LED亮暗控制

try:
    while True:
        distance = measure_distance()
        adjust_led_brightness(distance)
        print(f"Distance: {distance} cm, LED Brightness: {brightness*100}%")
        time.sleep(0.1)  # 每隔一段时间测量一次
except KeyboardInterrupt:
    print("Cleaning up...")
finally:
    GPIO.cleanup()  # 释放GPIO资源