# -*- coding:utf-8 -*-import time#引入pca9685的原始代码import machine#这里加入了灯光展示from light import Light#引入mqtt的pahoimport paho.mqtt.client as mqtt#本地ipMQTTHOST = "127.0.0.1"#mqtt的端口号MQTTPORT = 1883#初始化mqttClientmqttClient = mqtt.Client()#初始化pwmpwm = machine.PCA9685(0x40, debug=False)#设置pwm的频率pwm.setPWMFreq(50)#设置初始上下位置为中间，（500+2500）/2 = 1500up = 1500#设置初始左右位置为中间dw = 1500#设置灯的接口位置led = Light(17)# 消息处理函数def on_message_come(client, userdata, msg):topicmsg = str(msg.payload.decode("utf-8"))msgList = topicmsg.split(',', 1)#evalFunc的作用是将接受的命令字符串变成对应的方法进行执行evalFunc(msgList[0], msgList[1])# 连接MQTT服务器def on_mqtt_connect():mqttClient.connect(MQTTHOST, MQTTPORT, 60) # subscribe 消息订阅def on_subscribe(top):mqttClient.subscribe(top, 1) # 主题为"mqtt"mqttClient.on_message = on_message_come # 消息到来处理函数mqttClient.loop_forever()def evalFunc(func, n):#例如获取到了mqtt消息，right,1 ，这个表示执行向右1个单位，一共10个单位 print(str(func) + '(' + str(n) + ')')#eval可以调用方法进行执行eval(str(func) + '(' + str(n) + ')')#这个是恢复到初始位置def reset(n):led.blink()global upglobal dwfor i in range(1400,1500,1):pwm.setServoPulse(0,i)time.sleep(0.00025)for i in range(1400,1500,1):pwm.setServoPulse(1,i)time.sleep(0.00025)up = 1500dw = 1500#这个是向前进的代码def front(n):n = int(n)#这里我自定义n乘以5，是因为我之前每次执行一个单位，我想一次性执行5个单位的向下n = n * 5#灯光闪烁led.blink()global up#这里会判断是否已经到了阈值范围，如果到了则不执行下一步if up != 2500:#开启循环进行，从up到up+100*n,每次走100 * n个距离，当然这里你可以10 * n,这样舵机移动的角度非常小非常小#我这里500~2500一共是2000个，分20下100 * n,当n为1时，则移动20下从最前边到最后边，角度大概是从0度到180度这样，具体度数描述不太准确，请见谅#现在n = n * 5,意味着我只需要4下就从最前边到最后面，具体根据你的度数范围来，还有根据你移动的角度大小来决定舵机的速度for i in range(up,up+100*n,1*n):pwm.setServoPulse(0,i)time.sleep(0.00025)#每次执行完毕后，up都会变化up += 100*n#这里防止up变大超过2500，则变为2500if up > 2500:up = 2500def back(n):n = int(n)n = n * 5led.blink()global upif up != 500:for i in range(up,up-100*n,-1*n):pwm.setServoPulse(0,i)time.sleep(0.00025)up -= 100*nif up < 500:up = 500def left(n):n = int(n)n = n * 2led.blink()global dwif dw != 2500:for i in range(dw,dw+100*n,1*n):pwm.setServoPulse(1,i)time.sleep(0.00025)dw += 100*nif dw > 2500:dw = 2500def right(n):n = int(n)n = n * 2led.blink()global dwif dw != 500:for i in range(dw,dw-100*n,-1*n):pwm.setServoPulse(1,i)time.sleep(0.00025)dw -= 100*nif dw < 500:dw = 500if __name__ == '__main__':topic='mqtt'on_mqtt_connect()on_subscribe(topic)
下面是machine的代码，也就是PCA9685的python3测试代码
#!/usr/bin/pythonimport timeimport mathimport smbus# ============================================================================# Raspi PCA9685 16-Channel PWM Servo Driver# ============================================================================class PCA9685:# Registers/etc.__SUBADR1 = 0x02__SUBADR2 = 0x03__SUBADR3 = 0x04__MODE1 = 0x00__PRESCALE = 0xFE__LED0_ON_L= 0x06__LED0_ON_H= 0x07__LED0_OFF_L = 0x08__LED0_OFF_H = 0x09__ALLLED_ON_L = 0xFA__ALLLED_ON_H = 0xFB__ALLLED_OFF_L = 0xFC__ALLLED_OFF_H = 0xFDdef __init__(self, address=0x40, debug=False):self.bus = smbus.SMBus(1)self.address = addressself.debug = debugif (self.debug):print("Reseting PCA9685")self.write(self.__MODE1, 0x00)def write(self, reg, value):"Writes an 8-bit value to the specified register/address"self.bus.write_byte_data(self.address, reg, value)if (self.debug):print("I2C: Write 0x%02X to register 0x%02X" % (value, reg))def read(self, reg):"Read an unsigned byte from the I2C device"result = self.bus.read_byte_data(self.address, reg)if (self.debug):print("I2C: Device 0x%02X returned 0x%02X from reg 0x%02X" % (self.address, result & 0xFF, reg))return resultdef setPWMFreq(self, freq):"Sets the PWM frequency"prescaleval = 25000000.0 # 25MHzprescaleval /= 4096.0 # 12-bitprescaleval /= float(freq)prescaleval -= 1.0if (self.debug):print("Setting PWM frequency to %d Hz" % freq)print("Estimated pre-scale: %d" % prescaleval)prescale = math.floor(prescaleval + 0.5)if (self.debug):print("Final pre-scale: %d" % prescale)oldmode = self.read(self.__MODE1);newmode = (oldmode & 0x7F) | 0x10 # sleepself.write(self.__MODE1, newmode) # go to sleepself.write(self.__PRESCALE, int(math.floor(prescale)))self.write(self.__MODE1, oldmode)time.sleep(0.005)self.write(self.__MODE1, oldmode | 0x80)def setPWM(self, channel, on, off):"Sets a single PWM channel"self.write(self.__LED0_ON_L+4*channel, on & 0xFF)self.write(self.__LED0_ON_H+4*channel, on >> 8)self.write(self.__LED0_OFF_L+4*channel, off & 0xFF)self.write(self.__LED0_OFF_H+4*channel, off >> 8)if (self.debug):print("channel: %d LED_ON: %d LED_OFF: %d" % (channel,on,off))def setServoPulse(self, channel, pulse):"Sets the Servo Pulse,The PWM frequency must be 50HZ"pulse = pulse*4096/20000 #PWM frequency is 50HZ,the period is 20000usself.setPWM(channel, 0, int(pulse))if __name__=='__main__':pwm = PCA9685(0x40, debug=False)pwm.setPWMFreq(50)while True:# setServoPulse(2,2500)for i in range(500,2500,10): pwm.setServoPulse(0,i) time.sleep(0.02)for i in range(2500,500,-10):pwm.setServoPulse(0,i) time.sleep(0.02)
Python2的代码在此
#!/usr/bin/pythonimport timeimport mathimport smbus# ============================================================================# Raspi PCA9685 16-Channel PWM Servo Driver# ============================================================================class PCA9685:# Registers/etc.__SUBADR1 = 0x02__SUBADR2 = 0x03__SUBADR3 = 0x04__MODE1 = 0x00__PRESCALE = 0xFE__LED0_ON_L= 0x06__LED0_ON_H= 0x07__LED0_OFF_L = 0x08__LED0_OFF_H = 0x09__ALLLED_ON_L = 0xFA__ALLLED_ON_H = 0xFB__ALLLED_OFF_L = 0xFC__ALLLED_OFF_H = 0xFDdef __init__(self, address=0x40, debug=False):self.bus = smbus.SMBus(1)self.address = addressself.debug = debugif (self.debug):print("Reseting PCA9685")self.write(self.__MODE1, 0x00)def write(self, reg, value):"Writes an 8-bit value to the specified register/address"self.bus.write_byte_data(self.address, reg, value)if (self.debug):print("I2C: Write 0x%02X to register 0x%02X" % (value, reg))def read(self, reg):"Read an unsigned byte from the I2C device"result = self.bus.read_byte_data(self.address, reg)if (self.debug):print("I2C: Device 0x%02X returned 0x%02X from reg 0x%02X" % (self.address, result & 0xFF, reg))return resultdef setPWMFreq(self, freq):"Sets the PWM frequency"prescaleval = 25000000.0 # 25MHzprescaleval /= 4096.0 # 12-bitprescaleval /= float(freq)prescaleval -= 1.0if (self.debug):print("Setting PWM frequency to %d Hz" % freq)print("Estimated pre-scale: %d" % prescaleval)prescale = math.floor(prescaleval + 0.5)if (self.debug):print("Final pre-scale: %d" % prescale)oldmode = self.read(self.__MODE1);newmode = (oldmode & 0x7F) | 0x10 # sleepself.write(self.__MODE1, newmode) # go to sleepself.write(self.__PRESCALE, int(math.floor(prescale)))self.write(self.__MODE1, oldmode)time.sleep(0.005)self.write(self.__MODE1, oldmode | 0x80)def setPWM(self, channel, on, off):"Sets a single PWM channel"self.write(self.__LED0_ON_L+4*channel, on & 0xFF)self.write(self.__LED0_ON_H+4*channel, on >> 8)self.write(self.__LED0_OFF_L+4*channel, off & 0xFF)self.write(self.__LED0_OFF_H+4*channel, off >> 8)if (self.debug):print("channel: %d LED_ON: %d LED_OFF: %d" % (channel,on,off))def setServoPulse(self, channel, pulse):"Sets the Servo Pulse,The PWM frequency must be 50HZ"pulse = pulse*4096/20000 #PWM frequency is 50HZ,the period is 20000usself.setPWM(channel, 0, int(pulse))if __name__=='__main__':pwm = PCA9685(0x40, debug=False)pwm.setPWMFreq(50)while True:# setServoPulse(2,2500)for i in range(500,2500,10): pwm.setServoPulse(0,i) time.sleep(0.02)for i in range(2500,500,-10):pwm.setServoPulse(0,i) time.sleep(0.02)
具体的代码在此，包括python2和python3还有C的代码都在此，想多了解的可以下载一下，也可以不下载，代码也贴出来了，点击下载
