树莓派3无人驾驶学习笔记小车代码ing及L298N驱动电路资料

迈不过友情╰ 2023-02-14 15:53 109阅读 0赞

![l298n驱动电路接线图][l298n]

<table style="width:239px;">  L298N引脚功能说明  
 <thead> 
  <tr> 
   <th style="width:46px;">ENA</th> 
   <th style="width:59px;">IN1</th> 
   <th style="width:54px;">IN2</th> 
   <th style="width:57px;">直流电机状态</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td style="width:46px;">0</td> 
   <td style="width:59px;">X</td> 
   <td style="width:54px;">X</td> 
   <td style="width:57px;">停止</td> 
  </tr> 
  <tr> 
   <td style="width:46px;">1</td> 
   <td style="width:59px;">0</td> 
   <td style="width:54px;">0</td> 
   <td style="width:57px;">制动</td> 
  </tr> 
  <tr> 
   <td style="width:46px;">1</td> 
   <td style="width:59px;">0</td> 
   <td style="width:54px;">1</td> 
   <td style="width:57px;">正转</td> 
  </tr> 
  <tr> 
   <td style="width:46px;">1</td> 
   <td style="width:59px;">1</td> 
   <td style="width:54px;">0</td> 
   <td style="width:57px;">反转</td> 
  </tr> 
  <tr> 
   <td style="width:46px;">1</td> 
   <td style="width:59px;">1</td> 
   <td style="width:54px;">1</td> 
   <td style="width:57px;">制动</td> 
  </tr> 
 </tbody> 
</table>

PS:驱动供电电源(6-12V) 要接12V供电5V输出用来给单片机供电,不过树莓派一般用另外独立电源供电.  
使用说明:  
1、直流电机的驱动:  
该驱动板可驱动2路直流电机，使能端ENA、ENB 为高电平时有效，控制方  
式及直流电机状态如上表所示:  
直流电机进行PW\]M调速，需设置IN1和IN2，确定电机的转动方向，  
然后对使能端输出PWM脉冲，即可实现调速。注意当使能信号为0时，电机处于  
自由停止状态，当使能信号为1，且IN1和IN2为00或11时，电机处于制动状  
态，阻止电机转动。.

#coding=utf-8
    import RPi.GPIO as GPIO
    import time
    
    backMotorInput1=7
    backMotorInput2=11
    
    frontMotorInput1=13
    frontMotorInput2=15
    #两个使能端口：
    backMotorEn=12 
    frontMotorEn=16
    
    
    GPIO.setmode(GPIO.BOARD)
    
    #设置输出两个电机四根线对应的4个端口，要使用哪个端口需先设置声明
    GPIO.setup(backMotorInput1,GPIO.OUT)
    GPIO.setup(backMotorInput2,GPIO.OUT)
    GPIO.setup(frontMotorInput1,GPIO.OUT)
    GPIO.setup(frontMotorInput2,GPIO.OUT)
    #设置便能输出使用的通道口：
    GPIO.setup(backMotorEn,GPIO.OUT)
    GPIO.setup(frontMotorEn,GPIO.OUT)
    
    
    
    speed=30
    soft=80
    #设置脉冲控制电能输出，以控制车速：
    backMotorPwm=GPIO.PWM(backMotorEn,100)
    
    #设置脉冲控制电能输出，以控制转向力度：
    frontMotorPwm=GPIO.PWM(frontMotorEn,100)
    
    '''
    配置PWM :
    backMotorPwm = GPIO.PWM(backMotorEN, 100)
    第一个参数为在哪个端口输出PWM波
    第二个参数为方波频率为多少赫兹
    
    '''
    
    backMotorPwm.start(0)
    frontMotorPwm.start(0)
    '''开始输出PWM
    backMotorPwm.start(0)
    参数为占空比,单个周期中高电压占的比例
    可接受的参数为数字,范围是0~100
    
    改变频率
    p.ChangeFrequency(freq)   # where freq is the new frequency in Hz
    
    改变PWM的占空比:
    backMotorPwm.ChangeDutyCycle(66)
    参数为占空比
    可接受的参数为数字,范围是0~100
    
    停止输出PWM,节能:
    backMotorPwm.stop()
    '''
    
    #前进
    def carMoveForward():
    	GPIO.output(backMotorInput1,GPIO.LOW)
    	GPIO.output(backMotorInput2,GPIO.HIGH)
    	backMotorPwm.ChangeDutyCycle(speed)
    	
    #后退    
    def carMoveBackward():
    	GPIO.output(backMotorInput1,GPIO.HIGH)
    	GPIO.output(backMotorInput2,GPIO.LOW)
    	backMotorPwm.ChangeDutyCycle(speed)
    	
    
    #直行  使前轮失控制，设置转向控制使不能，前轮回正，：
    def carTurnStraight():
    	frontMotorPwm.ChangeDutyCycle(0)
    	
    	#用低电平，使‘不能’的方式，起不到失控作用了。
    	GPIO.output(frontMotorEn,GPIO.LOW)
    
    	
    	
    #左转
    def carTurnLeft():
    	#使前电机能:
    	#变速执行时优先于使能
    	frontMotorPwm.ChangeDutyCycle(soft)
    	GPIO.output(frontMotorEn,GPIO.HIGH)
    	GPIO.output(frontMotorInput1,GPIO.LOW)
    	GPIO.output(frontMotorInput2,GPIO.HIGH)
    	backMotorPwm.ChangeDutyCycle(20)
    	
    #右转
    def carTurnRight():
    	#使前电机能:
    	GPIO.output(frontMotorEn,GPIO.HIGH)
    	
    	GPIO.output(frontMotorInput1,GPIO.HIGH)
    	GPIO.output(frontMotorInput2,GPIO.LOW)
    	frontMotorPwm.ChangeDutyCycle(soft)
    	backMotorPwm.ChangeDutyCycle(20)
    
    	
    #停止
    def carStop():
    	GPIO.output(backMotorInput1,GPIO.LOW)
    	GPIO.output(backMotorInput2,GPIO.LOW)
    	GPIO.output(frontMotorInput1,GPIO.LOW)
    	GPIO.output(frontMotorInput2,GPIO.LOW)
    	
    #释放端口
    def cleanGPIO():
    	
    	#stop()后,依然是高电平，似无关于节能：
    	backMotorPwm.stop()
    	
    	#print(GPIO.input(16))获得frontMotorEn引脚即第16引脚的值
    	#代码GPIO.input(channel)将返回一个0 / GPIO.LOW / False或者1 / GPIO.HIGH / True.
    	frontMotorPwm.stop()
    		
    	GPIO.output(frontMotorEn,GPIO.LOW)
    	
    	GPIO.cleanup()
    	
    
    if __name__=='__main__':
    	carMoveForward()
    	time.sleep(2)
    	
    	carTurnLeft()
    	carMoveForward()
    	time.sleep(2)
    	
    	carStop()
    	time.sleep(3)
    	
    	carTurnStraight()
    	carMoveBackward()
    	time.sleep(2)
    	
    	carStop()
    	time.sleep(2)
    	
    	carTurnRight()
    	carMoveForward()
    	time.sleep(2)
    		
    	cleanGPIO()
    	
    
    
    '''
    	carMoveBackward()
    	
    	time.sleep(2)
    
    	carTurnRight()
    	time.sleep(2)
    	carTurnStraight()
    	carMoveForward()
    	time.sleep(2)
    '''

可参考:

RPI.GPIO Python使用手册:

1.中文[https://blog.csdn.net/oAlevel/article/details/79212949][https_blog.csdn.net_oAlevel_article_details_79212949]

2.英文[https://sourceforge.net/p/raspberry-gpio-python/wiki/BasicUsage/][https_sourceforge.net_p_raspberry-gpio-python_wiki_BasicUsage]

3[https://blog.csdn.net/qq\_27320195/article/details/104449211?ops\_request\_misc=%257B%2522request%255Fid%2522%253A%2522159188870519195264537063%2522%252C%2522scm%2522%253A%252220140713.130102334.pc%255Fblog.%2522%257D&request\_id=159188870519195264537063&biz\_id=0&utm\_medium=distribute.pc\_search\_result.none-task-blog-2~blog~first\_rank\_v1~rank\_blog\_v1-1-104449211.pc\_v1\_rank\_blog\_v1&utm\_term=RPi.GPIO+%E6%A8%A1%E5%9D%97%E7%BC%96%E7%A8%8B%E6%89%8B%E5%86%8C][https_blog.csdn.net_qq_27320195_article_details_104449211_ops_request_misc_257B_2522request_255Fid_2522_253A_2522159188870519195264537063_2522_252C_2522scm_2522_253A_252220140713.130102334.pc_255Fblog._2522_257D_request_id_159188870519195264537063_biz_id_0_utm_medium_distribute.pc_search_result.none-task-blog-2_blog_first_rank_v1_rank_blog_v1-1-104449211.pc_v1_rank_blog_v1_utm_term_RPi.GPIO_E6_A8_A1_E5_9D_97_E7_BC_96_E7_A8_8B_E6_89_8B_E5_86_8C]

[l298n]: https://img-blog.csdnimg.cn/20200611164852738.jpg?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2FobWN3dA==,size_16,color_FFFFFF,t_70
[https_blog.csdn.net_oAlevel_article_details_79212949]: https://blog.csdn.net/oAlevel/article/details/79212949
[https_sourceforge.net_p_raspberry-gpio-python_wiki_BasicUsage]: https://sourceforge.net/p/raspberry-gpio-python/wiki/BasicUsage/
[https_blog.csdn.net_qq_27320195_article_details_104449211_ops_request_misc_257B_2522request_255Fid_2522_253A_2522159188870519195264537063_2522_252C_2522scm_2522_253A_252220140713.130102334.pc_255Fblog._2522_257D_request_id_159188870519195264537063_biz_id_0_utm_medium_distribute.pc_search_result.none-task-blog-2_blog_first_rank_v1_rank_blog_v1-1-104449211.pc_v1_rank_blog_v1_utm_term_RPi.GPIO_E6_A8_A1_E5_9D_97_E7_BC_96_E7_A8_8B_E6_89_8B_E5_86_8C]: https://blog.csdn.net/qq_27320195/article/details/104449211?ops_request_misc=%257B%2522request%255Fid%2522%253A%2522159188870519195264537063%2522%252C%2522scm%2522%253A%252220140713.130102334.pc%255Fblog.%2522%257D&request_id=159188870519195264537063&biz_id=0&utm_medium=distribute.pc_search_result.none-task-blog-2~blog~first_rank_v1~rank_blog_v1-1-104449211.pc_v1_rank_blog_v1&utm_term=RPi.GPIO+%E6%A8%A1%E5%9D%97%E7%BC%96%E7%A8%8B%E6%89%8B%E5%86%8C