GPIO.output()函数的作用是什么

GPIO.output()函数的作用是将指定的GPIO引脚设置为指定的输出电平，可以控制外部电路的开关和状态。在树莓派等单片机平台上，通过GPIO引脚可以控制LED灯、继电器、蜂鸣器、舵机等外部电路。GPIO.output()函数需要传入两个参数，第一个参数是GPIO引脚的编号，第二个参数是输出电平，可以是HIGH（1）或LOW（0）。例如，GPIO.output(17, GPIO.HIGH)表示将GPIO17设置为高电平。

相关问题

import RPi.GPIO as GPIO from LCD1602 import LCD_1602 import time BtnPin = 13 R = 4 G = 12 B = 6 TRIG = 17 ECHO = 18 flag = 2 buzzer = 20 GPIO.setwarnings(False) GPIO.setmode(GPIO.BCM) GPIO.setup(TRIG,GPIO.OUT,initial=GPIO.LOW) GPIO.setup(ECHO,GPIO.IN) GPIO.setup(R,GPIO.OUT) GPIO.setup(B, GPIO.OUT) GPIO.setup(G, GPIO.OUT) GPIO.setup(buzzer, GPIO.OUT) GPIO.setup(BtnPin,GPIO.IN, pull_up_down=GPIO.PUD_UP) GPIO.output(buzzer,GPIO.HIGH) m_lcd = LCD_1602(Address=0x27, bus_id=1, bl=1) flag = m_lcd.lcd_init() while True: if GPIO.input(BtnPin) == 0: flag += 1 elif GPIO.input(BtnPin) == 1: pass if flag % 2 == 0: for i in range(10): GPIO.output(G,GPIO.LOW) GPIO.output(B,GPIO.LOW) GPIO.output(buzzer,GPIO.HIGH) GPIO.output(TRIG,GPIO.HIGH) time.sleep(0.000015) GPIO.output(TRIG,GPIO.LOW) while not GPIO.input(ECHO): pass t1 = time.time() while GPIO.input(ECHO): pass t2 = time.time() distance = round((t2-t1) * 340 / 2,5) if distance < 0.2: GPIO.output(B,GPIO.HIGH) GPIO.output(buzzer,GPIO.LOW) print("当前的距离为:",distance) a = '%f'%distance m_lcd.lcd_display_string(0, 0, 'The distance is') m_lcd.lcd_display_string(0, 1, a) m_lcd.lcd_display_string(8, 1, 'm') time.sleep(1) elif flag % 2 == 1: GPIO.output(G,GPIO.HIGH) GPIO.cleanup() ，我需要把灯和蜂鸣器还有其他的代码都用函数封装起来

好的，你可以尝试以下的代码：

import RPi.GPIO as GPIO 
from LCD1602 import LCD_1602 
import time 

BtnPin = 13 
R = 4 
G = 12 
B = 6 
TRIG = 17 
ECHO = 18 
buzzer = 20 

GPIO.setwarnings(False) 
GPIO.setmode(GPIO.BCM) 

GPIO.setup(TRIG, GPIO.OUT, initial=GPIO.LOW) 
GPIO.setup(ECHO, GPIO.IN) 
GPIO.setup(R, GPIO.OUT) 
GPIO.setup(B, GPIO.OUT) 
GPIO.setup(G, GPIO.OUT) 
GPIO.setup(buzzer, GPIO.OUT) 

GPIO.setup(BtnPin, GPIO.IN, pull_up_down=GPIO.PUD_UP) 
GPIO.output(buzzer, GPIO.HIGH) 

m_lcd = LCD_1602(Address=0x27, bus_id=1, bl=1) 
flag = m_lcd.lcd_init() 

def get_distance(): 
    GPIO.output(TRIG, GPIO.HIGH) 
    time.sleep(0.000015) 
    GPIO.output(TRIG, GPIO.LOW) 
    
    while not GPIO.input(ECHO): 
        pass 
        
    t1 = time.time() 
    
    while GPIO.input(ECHO): 
        pass 
        
    t2 = time.time() 
    distance = round((t2-t1) * 340 / 2, 5) 
    
    return distance 

def display_distance(distance): 
    a = '%f'%distance 
    m_lcd.lcd_display_string(0, 0, 'The distance is') 
    m_lcd.lcd_display_string(0, 1, a) 
    m_lcd.lcd_display_string(8, 1, 'm') 

def turn_on_red(): 
    GPIO.output(R, GPIO.HIGH) 

def turn_on_green(): 
    GPIO.output(G, GPIO.HIGH) 

def turn_on_blue(): 
    GPIO.output(B, GPIO.HIGH) 

def turn_off_leds(): 
    GPIO.output(R, GPIO.LOW) 
    GPIO.output(G, GPIO.LOW) 
    GPIO.output(B, GPIO.LOW) 

def turn_on_buzzer(): 
    GPIO.output(buzzer, GPIO.LOW) 

def turn_off_buzzer(): 
    GPIO.output(buzzer, GPIO.HIGH) 

def main(): 
    while True: 
        if GPIO.input(BtnPin) == 0: 
            flag += 1 
        elif GPIO.input(BtnPin) == 1: 
            pass 
        if flag % 2 == 0: 
            turn_off_leds() 
            turn_on_buzzer() 
            distance = get_distance() 
            if distance < 0.2: 
                turn_on_blue() 
                turn_off_buzzer() 
            display_distance(distance) 
            time.sleep(1) 
        elif flag % 2 == 1: 
            turn_on_green() 

if __name__ == '__main__': 
    main() 
    GPIO.cleanup() 

这个代码将灯和蜂鸣器的控制代码都封装成了函数，使代码更加模块化。

解释这段代码import RPi.GPIO as GPIO #引入RPi.GPIO库函数命名为GPIO import time #引入计时time函数 GPIO.setwarnings(False) GPIO.setmode(GPIO.BCM) #将GPIO编程方式设置为BCM模式，基于插座引脚编号 #接口定义 TRIG = 21 #将超声波模块TRIG口连接到树莓派Pin21 ECHO = 22 #将超声波模块ECHO口连接到树莓派Pin22 INT1 = 16 #将L298 INT1口连接到树莓派Pin16 INT2 = 17 #将L298 INT2口连接到树莓派Pin17 INT3 = 18 INT4 = 19 #输出模式 GPIO.setup(TRIG,GPIO.OUT) GPIO.setup(ECHO,GPIO.IN) GPIO.setup(INT1,GPIO.OUT) GPIO.setup(INT2,GPIO.OUT) GPIO.setup(INT3,GPIO.OUT) GPIO.setup(INT4,GPIO.OUT) #一直前进函数 def Forward(): GPIO.output(INT1,GPIO.HIGH) GPIO.output(INT2,GPIO.LOW) GPIO.output(INT3,GPIO.LOW) GPIO.output(INT4,GPIO.HIGH) #后退指定时间函数 def Back_time(time_sleep): GPIO.output(INT1,GPIO.HIGH) GPIO.output(INT2,GPIO.LOW) GPIO.output(INT3,GPIO.HIGH) GPIO.output(INT4,GPIO.LOW) time.sleep(time_sleep) #rght指定时间函数 def right_time(time_sleep): GPIO.output(INT1,GPIO.LOW) GPIO.output(INT2,GPIO.LOW) GPIO.output(INT3,GPIO.HIGH) GPIO.output(INT4,GPIO.LOW) time.sleep(time_sleep) #停止函数 def Stop(): GPIO.output(INT1,GPIO.LOW) GPIO.output(INT2,GPIO.LOW) GPIO.output(INT3,GPIO.LOW) GPIO.output(INT4,GPIO.LOW) # 超声波测距函数 def distance(): GPIO.output(TRIG, 0) time.sleep(0.000002) GPIO.output(TRIG, 1) time.sleep(0.00001) GPIO.output(TRIG, 0) while GPIO.input(ECHO) == 0: pass emitTime = time.time() while GPIO.input(ECHO) == 1: pass acceptTime = time.time() totalTime = acceptTime - emitTime distanceForReturn = totalTime * 340 / 2 * 100 return distanceForReturn def loop(): while True: dis= distance() if dis<=25: while dis<=25: Back_time(0.2) right_time(0.2) dis=distance() else: Forward() if __name__ == '__main__':

这是一段Python代码，主要是用于控制树莓派与超声波模块及L298电机驱动模块的交互，实现小车的自动避障功能。代码中首先引入了RPi.GPIO库和time库，然后设置了GPIO的编程方式和定义了超声波模块TRIG口和ECHO口以及L298电机驱动模块INT1口、INT2口、INT3口、INT4口的接口。接着定义了一些控制小车行驶的函数，如前进函数、后退指定时间函数、右转指定时间函数和停止函数。最后定义了一个循环函数loop()，其中通过调用超声波测距函数distance()来获取小车与障碍物的距离，并根据距离的不同来判断小车的行动，如果距离小于等于25cm，就会依次执行后退和右转操作，直到距离大于25cm，就会执行前进操作。代码中的if __name__ == '__main__':语句表示如果该模块是被直接运行的，则执行loop()函数，如果是被作为模块导入其他模块的，则不执行。