【学习笔记】——16路PWM舵机驱动板(PCA 9685) + Arduino

16路12位PWM信号发生器，节省主机资源，值得拥有。
先对单个舵机尝试一下，了解一下PWM
PWM

一个非常简单的舵机例子：
#include <Servo.h>  
#define PIN_SERVO 10
Servo myservo;  
void setup()  
{  
  myservo.attach(PIN_SERVO);  
}  
void loop()  
{  
  myservo.write(0);  
  delay(1000);  
  myservo.write(80);  
  delay(1000);  
  myservo.write(160);  
  delay(1000);  
  myservo.write(80);  
  delay(1000);  
  myservo.write(0);  
  delay(1000);  
} 

#include <Servo.h>  
#define PIN_SERVO 9
int i=0;
Servo myservo;  
void setup()  
{  
  myservo.attach(PIN_SERVO);  
}  
void loop()  
{  
for(i=0;i<160;i++)
{
  myservo.write(i);  
  delay(30);
}
for(i=160;i>0;i--)
{
  myservo.write(i);  
  delay(30);
}
delay(1000);
} 

==主要参数==

电压：DC5V供电

通信接口:I2C

产品尺寸：15+61mm

工作电压：3-5V

逻辑电压：3-5V

V+引脚：5V-6V

工作频率：40-1000HZ

==接线图==

舵机 舵机驱动板

PWM（黄线） PWM（黄色）

扫描二维码关注公众号，回复： 2999123 查看本文章

VCC（红线） V+（红色）

GND（黑或褐线） GND（黑色）
==例子程序==
16路舵机同时转动。原理是定义脉宽最大和最小，通过改变0-15号舵机的脉宽大小实现角度转动

/*************************************************** 
  This is an example for our Adafruit 16-channel PWM & Servo driver
  Servo test - this will drive 16 servos, one after the other
  这是我们的Adafruit 16通道PWM和伺服驱动器的一个例子，驱动16个伺服电机

  Pick one up today in the adafruit shop!
  ------> http://www.adafruit.com/products/815

  These displays use I2C to communicate, 2 pins are required to  
  interface. For Arduino UNOs, thats SCL -> Analog 5, SDA -> Analog 4
  这些显示器使用I2C进行通信，需要2个引脚。
  接口。对于ARDUINO UNOS，这是SCL->模拟5，SDA - >模拟4

  ****************************************************/

#include <Wire.h>
#include <Adafruit_PWMServoDriver.h>

// called this way, it uses the default address 0x40
////以这种方式调用，它使用默认地址0x40。
Adafruit_PWMServoDriver pwm = Adafruit_PWMServoDriver();
// you can also call it with a different address you want
//Adafruit_PWMServoDriver pwm = Adafruit_PWMServoDriver(0x41);
//也可以用不同的地址调用它

/* Depending on your servo make, the pulse width min and max may vary, you  want these to be as small/large as possible without hitting the hard stop
 for max range. You'll have to tweak them as necessary to match the servos you
have!*/
/*根据你的伺服制作，脉冲宽度最小和最大可能变化，你想要这些尽可能小大而不碰到
硬停止，对于最大范围。你必须调整它们以匹配你的伺服系统！*/
#define SERVOMIN  150 // this is the 'minimum' pulse length count (out of 4096)
//这是“最小”脉冲长度计数（在4096）中
#define SERVOMAX  600 // this is the 'maximum' pulse length count (out of 4096)
//这是“最大”脉冲长度计数（在4096中）

// our servo # counter
//uint8_t servonum = 0;

void setup() {
   Serial.begin(9600);
   Serial.println("16 channel Servo test!");

  pwm.begin();

   pwm.setPWMFreq(60);  // Analog servos run at ~60 Hz updates
   ////模拟伺服在60赫兹更新下运行
}

// you can use this function if you'd like to set the pulse length in seconds
// e.g. setServoPulse(0, 0.001) is a ~1 millisecond pulse width. its not precise!
//如果您想以秒为单位设置脉冲长度，则可以使用此函数。
//例如SET伺服脉冲（0，0.001）是一个1毫秒的脉冲宽度。它不是
void setServoPulse(uint8_t n, double pulse) {
   double pulselength;//精度浮点数

   pulselength = 1000000;   // 1,000,000 us per second 每秒100万
   pulselength /= 60;   // 60 Hz
   Serial.print(pulselength); Serial.println(" us per period"); 
   pulselength /= 4096;  // 12 bits of resolution 12位分辨率
   Serial.print(pulselength); Serial.println(" us per bit"); 
   pulse *= 1000;
   pulse /= pulselength;
   Serial.println(pulse);
   pwm.setPWM(n, 0, pulse);
}

void loop() {
   // Drive each servo one at a time
   //Serial.println(servonum);
   //每次驱动一个伺服驱动器
//串行打印（伺服）；
   for (uint16_t pulselen = SERVOMIN; pulselen < SERVOMAX; pulselen++) {
     pwm.setPWM(0, 0, pulselen);
     pwm.setPWM(1, 0, pulselen);
     pwm.setPWM(2, 0, pulselen);
     pwm.setPWM(3, 0, pulselen);
     pwm.setPWM(4, 0, pulselen);
     pwm.setPWM(5, 0, pulselen);
     pwm.setPWM(6, 0, pulselen);
     pwm.setPWM(7, 0, pulselen);
     pwm.setPWM(8, 0, pulselen);
     pwm.setPWM(9, 0, pulselen);
     pwm.setPWM(10, 0, pulselen);
     pwm.setPWM(11, 0, pulselen);
     pwm.setPWM(12, 0, pulselen);
     pwm.setPWM(13, 0, pulselen);
     pwm.setPWM(14, 0, pulselen);

     pwm.setPWM(15, 0, pulselen);
   }
   delay(500);
   for (uint16_t pulselen = SERVOMAX; pulselen > SERVOMIN; pulselen--) {
     pwm.setPWM(0, 0, pulselen);
     pwm.setPWM(1, 0, pulselen);
     pwm.setPWM(2, 0, pulselen);
     pwm.setPWM(3, 0, pulselen);
     pwm.setPWM(4, 0, pulselen);
     pwm.setPWM(5, 0, pulselen);
     pwm.setPWM(6, 0, pulselen);
     pwm.setPWM(7, 0, pulselen);
     pwm.setPWM(8, 0, pulselen);
     pwm.setPWM(9, 0, pulselen);
     pwm.setPWM(10, 0, pulselen);
     pwm.setPWM(11, 0, pulselen);
     pwm.setPWM(12, 0, pulselen);
     pwm.setPWM(13, 0, pulselen);
     pwm.setPWM(14, 0, pulselen);

     pwm.setPWM(15, 0, pulselen);
   }
   delay(500);

}

16路舵机驱动板资料（内含模块级联说明）：https://pan.baidu.com/s/1gfhFGDP

例子2：

#include <Wire.h>
#include <Adafruit_PWMServoDriver.h>

// called this way, it uses the default address 0x40
Adafruit_PWMServoDriver pwm = Adafruit_PWMServoDriver();

// our servo # counter
//uint8_t servonum = 0;

void setup() {
  Serial.begin(9600);
  Serial.println("16 channel Servo test!");

  pwm.begin();

  pwm.setPWMFreq(50);  // Analog servos run at ~50 Hz updates模拟伺服运行在50赫兹更新
}

void loop() {
  //setServoPulse(0, 0.001);
  //setServoPulseMS(1, 50);
  pwm.setPin(0,0,0);
  pwm.setPin(1,4096,0);
  pwm.setPin(2,(0.5/20.0)*4096,0);
}

自带例程

/*************************************************** 
  This is an example for our Adafruit 16-channel PWM & Servo driver
  PWM test - this will drive 16 PWMs in a 'wave'

  Pick one up today in the adafruit shop!
  ------> http://www.adafruit.com/products/815

  These displays use I2C to communicate, 2 pins are required to  
  interface. For Arduino UNOs, thats SCL -> Analog 5, SDA -> Analog 4

  Adafruit invests time and resources providing this open source code, 
  please support Adafruit and open-source hardware by purchasing 
  products from Adafruit!

  Written by Limor Fried/Ladyada for Adafruit Industries.  
  BSD license, all text above must be included in any redistribution
这是我们的AdfRuIT 16通道PWM和伺服驱动器的一个例子。
PWM测试-这将驱动16个波姆斯在“波”
今天在AdfRuIT商店挑选一个！
------HTTP://www. AdAfRuIT.COM/PROSTS/815
这些显示器使用I2C进行通信，需要2个引脚。
接口。对于ARDUINO UNOS，这是SCL->模拟5，SDA - >模拟4
ADAFRUIT投入时间和资源来提供这个开源代码，
请通过购买支持AdfRuIT和开源硬件
来自AdfRuIT的产品！
由Limor Fray/Lajayad撰写的AdfuRIT产业。
BSD许可证，以上所有文本必须包含在任何再分配中
***********************************************/

#include <Wire.h>
#include <Adafruit_PWMServoDriver.h>
//以这种方式调用，它使用默认地址0x40。
// called this way, it uses the default address 0x40
Adafruit_PWMServoDriver pwm = Adafruit_PWMServoDriver();
// you can also call it with a different address you want
//Adafruit_PWMServoDriver pwm = Adafruit_PWMServoDriver(0x41);
//你也可以用不同的地址称呼它。
//ADAFRUITIGPWM伺服驱动器PWM＝ADAFRUITIGPWM伺服驱动器（0x41）；

void setup() {
  Serial.begin(9600);
  Serial.println("16 channel PWM test!");

  // if you want to really speed stuff up, you can go into 'fast 400khz I2C' mode
  // some i2c devices dont like this so much so if you're sharing the bus, watch
  // out for this!
  //如果你真的想加快速度，你可以进入“快速400千赫I2C”模式。
//一些I2C设备不太喜欢这个，所以如果你在共享公共汽车，请注意。
//为了这个！

  pwm.begin();
  pwm.setPWMFreq(1600);  // This is the maximum PWM frequency这是最大PWM频率

  // save I2C bitrate
  uint8_t twbrbackup = TWBR;
  // must be changed after calling Wire.begin() (inside pwm.begin())
  //保存I2C比特率
//必须在调用Word.No.2之后更改（内部PWM（开始））
  TWBR = 12; // upgrade to 400KHz!升级到400千赫！

}

void loop() {
  // Drive each PWM in a 'wave'
  //在“波”中驱动每个PWM
  for (uint16_t i=0; i<4096; i += 8) {
    for (uint8_t pwmnum=0; pwmnum < 16; pwmnum++) {
      pwm.setPWM(pwmnum, 0, (i + (4096/16)*pwmnum) % 4096 );
    }
  }
}