伺服电机不会持续旋转，这与原始 Arduino 代码的意图不同

Question

我想不停地循环移动伺服电机！怎么了？

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

Adafruit_PWMServoDriver pwm = Adafruit_PWMServoDriver();

int motors[] = {0, 1, 2, 3};
int degrees[] = {0, 0, 0, 0};

void setup() {
  Serial.begin(9600);
  pwm.begin();
  pwm.setPWMFreq(50);
  pwm.setOscillatorFrequency(27000000); 
  
  for(int i=0; i<15; i++){
    pwm.setPWM(i, 0, 150);   
  }
  
  Serial.setTimeout(10);
}

void joystick_val(int pin){
  Serial.print(pin);
  Serial.print("   ");  
}

void Move_motor(int motor, int degree, int int_val){
  if(int_val <= 1){
    degree += 5;
    if(degree > 180) degree = 180;
        
    int pul = map(degree,0,180,150,600);
    pwm.setPWM(motor, 0, pul);
  }
  
  else if(int_val >= 4){
    degree -= 5;
    if(degree < 0) degree = 0;
        
    int pul = map(degree,0,180,150,600);
    pwm.setPWM(motor, 0, pul);
  }
  
}

void loop() { 

  //int e = Serial.parseInt();
  int analogPin[] = {analogRead(A0), analogRead(A1), analogRead(A2), analogRead(A3)};
  int int_Pin[] = { map(analogPin[0], 0, 1023, 0, 5),
                    map(analogPin[1], 0, 1023, 0, 5),
                    map(analogPin[2], 0, 1023, 0, 5),
                    map(analogPin[3], 0, 1023, 0, 5)
                  };
  int Pin_amount = sizeof(analogPin)-4;
  
  Move_motor(motors[0], degrees[0], map(analogPin[0], 0, 1023, 0, 5));
  Move_motor(motors[1], degrees[1], map(analogPin[1], 0, 1023, 0, 5));
  Move_motor(motors[2], degrees[2], map(analogPin[2], 0, 1023, 0, 5));
  Move_motor(motors[3], degrees[3], map(analogPin[3], 0, 1023, 0, 5));


  for(int j=0; j<Pin_amount; j++){
    Serial.print(map(analogPin[j], 0, 1023, 0, 5));
    Serial.print("   "); 
  }       
  
  Serial.println("");
}

原本，只要握住连接到电机的操纵杆，伺服电机就必须保持旋转，只有松开操纵杆才停止。然而，当摇杆移动时，伺服电机会在旋转一瞬间后停止，而不是连续旋转。

我尝试使用“for”循环，也尝试改变 PWM 的频率。我想要的是使代码功能相同，而无需编写四次 Move_motor 函数。预先感谢您。

Answer 1

1. 当您更改

   degree

   中的

   Move_motor

   时，它只会更改本地值。

2. 它不会更改全局数组degrees

   ，因此当调用

   degree

   时，

   Move_motor

   的值是

   always 0。

3. degree

    只会是 0 或 5

为了解决这个问题，我们

可以将degrees

作为指针传递给

Move_motor

。

但是，有很多[不必要的]重复代码。

解决此问题的最佳方法是使用单个

struct

 数组，而不是使用相同值索引的多个数组。

---

这是一个重构版本。注释为：

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

Adafruit_PWMServoDriver pwm = Adafruit_PWMServoDriver();

// per-motor control
typedef struct mctl {
    int motidx;                         // motor index
    int apin;                           // AnalogRead port number

    int aval;                           // AnalogRead value
    int ival;                           // int of aval

    int degree;                         // current rotation
    int pul;                            // old motor pul value
} mctl_t;

#define NCTL        4
mctl_t controls[NCTL];

void
setup(void)
{
    Serial.begin(9600);
    pwm.begin();
    pwm.setPWMFreq(50);
    pwm.setOscillatorFrequency(27000000);

    for (int i = 0; i < 15; i++)
        pwm.setPWM(i, 0, 150);

    Serial.setTimeout(10);

    int aport[] = { A0, A1, A2, A3 };
    for (mctl_t mctl = &controls[0];  mctl < &controls[NCTL];  ++mctl) {
        int motidx = mctl - controls;
        mctl->motidx = motidx;
        mctl->aport = aport[motidx];
        mctl->pul = 0x7FFFFFFFF;
    }
}

void
joystick_val(int pin)
{
    Serial.print(pin);
    Serial.print("   ");
}

void
move_motor(mctl_t *mctl)
{
    int degree = mctl->degree;
    int setflg = 0;

    int int_val = map(mctl->aval, 0, 1023, 0, 5),

    do {
        if (int_val <= 1) {
            degree += 5;
            setflg = 1;
            break;
        }

        if (int_val >= 4) {
            degree -= 5;
            setflg = 1;
            break;
        }

        // do nothing???
    } while (0);

    if (degree > 180)
        degree = 180;
    if (degree < 0)
        degree = 0;

    do {
        if (! setflg)
            break;

        int pul = map(degree, 0, 180, 150, 600);

        // optional speedup: don't send value if hasn't changed since the last
        // time
        if (pul == mctl->pul)
            break;

        pwm.setPWM(mctl->motidx, 0, pul);

        // remember the value we just output
        mctl->pul = pul;
    } while (0);

    // save updated values
    mctl->degree = degree;
    mctl->ival = int_val;
}

void
loop(void)
{

    // grab all values quickly
    for (mctl_t mctl = &controls[0];  mctl < &controls[NCTL];  ++mctl)
        mctl->aval = AnalogRead(mctl->apin);

    // change all motor values
    for (mctl_t mctl = &controls[0];  mctl < &controls[NCTL];  ++mctl)
        move_motor(mctl);

    // show all values
    for (mctl_t mctl = &controls[0];  mctl < &controls[NCTL];  ++mctl) {
        Serial.print(mctl->ival);
        Serial.print("   ");
    }
    Serial.println("");
}