不带舵机驱动代码：
有障碍物的话------就右转或者左转避开
#!/usr/bin/env pythonimport RPi.GPIO as GPIOimport timeimport sys#BCM编码PWMA = 18AIN1 = 22AIN2 = 27PWMB = 23BIN1 = 25BIN2 = 24BtnPin = 19#这三个引脚不晓得干啥的Gpin = 5Rpin = 6#超声波工作引脚TRIG = 20 ##设置Trig和ECHO俩个引脚ECHO = 21def t_up(speed,t_time):L_Motor.ChangeDutyCycle(speed)GPIO.output(AIN2,False)#AIN2GPIO.output(AIN1,True) #AIN1R_Motor.ChangeDutyCycle(speed)GPIO.output(BIN2,False)#BIN2GPIO.output(BIN1,True) #BIN1time.sleep(t_time)def t_stop(t_time):L_Motor.ChangeDutyCycle(0)GPIO.output(AIN2,False)#AIN2GPIO.output(AIN1,False) #AIN1R_Motor.ChangeDutyCycle(0)GPIO.output(BIN2,False)#BIN2GPIO.output(BIN1,False) #BIN1time.sleep(t_time)def t_down(speed,t_time):L_Motor.ChangeDutyCycle(speed)GPIO.output(AIN2,True)#AIN2GPIO.output(AIN1,False) #AIN1R_Motor.ChangeDutyCycle(speed)GPIO.output(BIN2,True)#BIN2GPIO.output(BIN1,False) #BIN1time.sleep(t_time)def t_left(speed,t_time):L_Motor.ChangeDutyCycle(speed)GPIO.output(AIN2,True)#AIN2GPIO.output(AIN1,False) #AIN1R_Motor.ChangeDutyCycle(speed)GPIO.output(BIN2,False)#BIN2GPIO.output(BIN1,True) #BIN1time.sleep(t_time)def t_right(speed,t_time):L_Motor.ChangeDutyCycle(speed)GPIO.output(AIN2,False)#AIN2GPIO.output(AIN1,True) #AIN1R_Motor.ChangeDutyCycle(speed)GPIO.output(BIN2,True)#BIN2GPIO.output(BIN1,False) #BIN1time.sleep(t_time)def keysacn():##按键开关引脚val = GPIO.input(BtnPin)#输入引脚while GPIO.input(BtnPin) == False:#低电平val = GPIO.input(BtnPin)while GPIO.input(BtnPin) == True:#高电平time.sleep(0.01)val = GPIO.input(BtnPin)if val == True:GPIO.output(Rpin,1)while GPIO.input(BtnPin) == False:GPIO.output(Rpin,0)else:GPIO.output(Rpin,0)def setup():GPIO.setwarnings(False)GPIO.setmode(GPIO.BCM)GPIO.setup(TRIG, GPIO.OUT)GPIO.setup(ECHO, GPIO.IN)GPIO.setup(Gpin, GPIO.OUT)# Set Green Led Pin mode to outputGPIO.setup(Rpin, GPIO.OUT)# Set Red Led Pin mode to outputGPIO.setup(BtnPin, GPIO.IN, pull_up_down=GPIO.PUD_UP) # Set BtnPin's mode is input, and pull up to high level(3.3V)GPIO.setup(AIN2,GPIO.OUT)GPIO.setup(AIN1,GPIO.OUT)GPIO.setup(PWMA,GPIO.OUT)GPIO.setup(BIN1,GPIO.OUT)GPIO.setup(BIN2,GPIO.OUT)GPIO.setup(PWMB,GPIO.OUT)def distance():#同超声波测量距离原理GPIO.output(TRIG, 0)time.sleep(0.000002)GPIO.output(TRIG, 1)time.sleep(0.00001)GPIO.output(TRIG, 0)#准备开始阶段while GPIO.input(ECHO) == 0:a = 0time1 = time.time()while GPIO.input(ECHO) == 1:a = 1time2 = time.time()during = time2 - time1return during * 340 / 2 * 100def loop():#判断要不要规避while True:dis = distance()if (dis < 40) == True:#前方有障碍物,进行规避右转while (dis < 40) == True:#距离《40t_down(30,0.5)#占空比改变速度t_right(30,0.1)dis = distance()else:t_up(50,0)print(dis, 'cm')print('')def destroy():GPIO.cleanup()if __name__ == "__main__":setup() #设置对应输入输出引脚L_Motor= GPIO.PWM(PWMA,100) #左边使能A#L_Motor.start(0)R_Motor = GPIO.PWM(PWMB,100)R_Motor.start(0)t_stop(.1)# keysacn()#不需要这一步也行！！！try:loop()except KeyboardInterrupt:destroy()
二、带舵机模块：
舵机运转：（如果舵机不是由树莓派供电的话，需要将该电源与树莓派共地，也就是说电源的负极必须与树莓派任意一个GND连接，否则会出现舵机控制失常等现象。）如果
DutyCycle = angle/18 + 2-------通过改变占空比控制舵机转换角度0度对应——2%占空比90度对应——7%占空比180度——12%占空比
工作原理：
控制电路板接受来自信号线的控制信号，控制电机转动，电机带动一系列齿轮组，减速后传动至输出舵盘。舵机的输出轴和位置反馈电位计是相连的，舵盘转动的同时，带动位置反馈电位计，电位计将输出一个电压信号到控制电路板，进行反馈，然后控制电路板根据所在位置决定电机的转动方向和速度，从而达到目标停止。
带舵机小车代码 ：
#!/usr/bin/env pythonfrom Adafruit_PWM_Servo_Driver import PWMimport RPi.GPIO as GPIOimport timeimport sysPWMA = 18AIN1 = 22AIN2 = 27PWMB = 23BIN1 = 25BIN2 = 24BtnPin = 19#舵机接口Gpin = 5Rpin = 6TRIG = 20ECHO = 21# Initialise the PWM device using the default address# bmp = PWM(0x40, debug=True)pwm = PWM(0x40,debug = False)servoMin = 150 # Min pulse length out of 4096servoMax = 600 # Max pulse length out of 4096def setServoPulse(channel, pulse):pulseLength = 1000000.0 # 1,000,000 us per secondpulseLength /= 50.0 # 60 Hzprint("%d us per period" % pulseLength)pulseLength /= 4096.0 # 12 bits of resolutionprint("%d us per bit" % pulseLength)pulse *= 1000.0pulse /= (pulseLength*1.0)# pwmV=int(pluse)print("pluse: %f " % (pulse))pwm.setPWM(channel, 0, int(pulse))#调用其他函数库#Angle to PWMdef write(servonum,x): #改变占空比-----》改变舵机角度！！！！！！！！！！！！！！！！！！！！y=x/90.0+0.5y=max(y,0.5)y=min(y,2.5)setServoPulse(servonum,y)def t_up(speed,t_time):L_Motor.ChangeDutyCycle(speed)GPIO.output(AIN2,False)#AIN2GPIO.output(AIN1,True) #AIN1R_Motor.ChangeDutyCycle(speed)GPIO.output(BIN2,False)#BIN2GPIO.output(BIN1,True) #BIN1time.sleep(t_time)def t_stop(t_time):L_Motor.ChangeDutyCycle(0)GPIO.output(AIN2,False)#AIN2GPIO.output(AIN1,False) #AIN1R_Motor.ChangeDutyCycle(0)GPIO.output(BIN2,False)#BIN2GPIO.output(BIN1,False) #BIN1time.sleep(t_time)def t_down(speed,t_time):L_Motor.ChangeDutyCycle(speed)GPIO.output(AIN2,True)#AIN2GPIO.output(AIN1,False) #AIN1R_Motor.ChangeDutyCycle(speed)GPIO.output(BIN2,True)#BIN2GPIO.output(BIN1,False) #BIN1time.sleep(t_time)def t_left(speed,t_time):L_Motor.ChangeDutyCycle(speed)GPIO.output(AIN2,True)#AIN2GPIO.output(AIN1,False) #AIN1R_Motor.ChangeDutyCycle(speed)GPIO.output(BIN2,False)#BIN2GPIO.output(BIN1,True) #BIN1time.sleep(t_time)def t_right(speed,t_time):L_Motor.ChangeDutyCycle(speed)GPIO.output(AIN2,False)#AIN2GPIO.output(AIN1,True) #AIN1R_Motor.ChangeDutyCycle(speed)GPIO.output(BIN2,True)#BIN2GPIO.output(BIN1,False) #BIN1time.sleep(t_time)def keysacn():val = GPIO.input(BtnPin)while GPIO.input(BtnPin) == False:val = GPIO.input(BtnPin)while GPIO.input(BtnPin) == True:time.sleep(0.01)val = GPIO.input(BtnPin)if val == True:GPIO.output(Rpin,1)while GPIO.input(BtnPin) == False:GPIO.output(Rpin,0)else:GPIO.output(Rpin,0)def setup():GPIO.setwarnings(False)GPIO.setmode(GPIO.BCM)GPIO.setup(TRIG, GPIO.OUT)GPIO.setup(ECHO, GPIO.IN)GPIO.setup(Gpin, GPIO.OUT)# Set Green Led Pin mode to outputGPIO.setup(Rpin, GPIO.OUT)# Set Red Led Pin mode to outputGPIO.setup(BtnPin, GPIO.IN, pull_up_down=GPIO.PUD_UP) # Set BtnPin's mode is input, and pull up to high level(3.3V)GPIO.setup(AIN2,GPIO.OUT)GPIO.setup(AIN1,GPIO.OUT)GPIO.setup(PWMA,GPIO.OUT)GPIO.setup(BIN1,GPIO.OUT)GPIO.setup(BIN2,GPIO.OUT)GPIO.setup(PWMB,GPIO.OUT)pwm.setPWMFreq(50) # Set frequency to 60 Hzdef distance(): #测量距离函数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:a = 0time1 = time.time()while GPIO.input(ECHO) == 1:a = 1time2 = time.time()during = time2 - time1return during * 340 / 2 * 100def front_detection():#测量前后间距write(0,90)time.sleep(0.5)dis_f = distance()return dis_fdef left_detection():#write(0, 175)time.sleep(0.5)dis_l = distance()return dis_ldef right_detection():write(0,5)time.sleep(0.5)dis_r = distance()return dis_rdef loop():while True:dis1 = front_detection()if (dis1 < 40) == True:t_stop(0.2)t_down(50,0.5)t_stop(0.2)dis2 = left_detection()dis3 = right_detection()if (dis2 < 40) == True and (dis3 < 40) == True:t_left(50,1)elif (dis2 > dis3) == True:t_left(50,0.3)t_stop(0.1)else:t_right(50,0.3)t_stop(0.1)else:t_up(60,0)# print dis1, 'cm'# print ''def destroy():GPIO.cleanup()if __name__ == "__main__":setup()L_Motor= GPIO.PWM(PWMA,100)L_Motor.start(0)R_Motor = GPIO.PWM(PWMB,100)R_Motor.start(0)keysacn()try:loop()except KeyboardInterrupt:destroy()
