Arduino: The delay that lasts forever答案

【问题标题】：Arduino: The delay that lasts foreverArduino: The delay that lasts forever
【发布时间】：2022-12-02 06:28:51
【问题描述】：

I'm coding a hydroponics project where I trigger a servo to turn on a sprayer, then a pump is turned on and off and the entire thing needs to repeat.

The whole thing works great except for the last delay cycle, which never ends and so the loop cycle never repeats, it only runs once.

Any ideas on why this is happening?

The code:

#include <Wire.h>
#include <Adafruit_PWMServoDriver.h>
Adafruit_PWMServoDriver pwm = Adafruit_PWMServoDriver();
#define SERVOMIN  250 
#define SERVOMAX  650 
#define USMIN  600 
#define USMAX  2400 
#define SERVO_FREQ 50 
uint8_t servonum = 0;

int D3 = 3;
int D4 = 4;

void setup() {
  Serial.begin(9600);
  Serial.println("Reboot!");
  pinMode(D3, OUTPUT);
  pinMode(D4, OUTPUT);  
  pwm.begin();
  pwm.setOscillatorFrequency(27000000);
  pwm.setPWMFreq(SERVO_FREQ);  // Analog servos run at ~50 Hz updates
  delay(10);
}

void loop() {
  Serial.println('On');
  digitalWrite(D3, LOW); 
  digitalWrite(D4, LOW); 

  pwm.setPWM(servonum, 0, 170);
  delay(500);
  pwm.setPWM(servonum, 0, 300);


  // 
  delay(0.5*1000*60);
  //delay(3000);

  // Off for 10 minutes
  Serial.println('Off');
  pwm.setPWM(servonum, 0, 170);
  delay(500);
  pwm.setPWM(servonum, 0, 300);

  Serial.println('Pump on');
  digitalWrite(D3, HIGH); 
  digitalWrite(D4, HIGH); 
  delay(15*1000); // TURN ON PUMP FOR 15 seconds

  Serial.println('Pump Off');
  digitalWrite(D3, LOW); 
  digitalWrite(D4, LOW); // TURN OFF PUMP, TURN ON 

  delay(2*1000*60); // This is the delay that never ends, it's supposed to be 2 minutes long...

}


void setServoPulse(uint8_t n, double pulse) {
  double pulselength;
  pulselength = 1000000;   // 1,000,000 us per second
  pulselength /= SERVO_FREQ;   // Analog servos run at ~60 Hz updates

  pulselength /= 4096;  // 12 bits of resolution

  pulse *= 1000000;  // convert input seconds to us
  pulse /= pulselength;

  pwm.setPWM(n, 0, pulse);
}

【问题讨论】：

so everything else is working fine? you receive Pump Off and the pump goes off?
Yes, servo clicks the pump button, pump turns on, pump turns off, then nothing.
What size processor are you using 16 or 32-bit? Just wondering whether unsigned long is smaller than 120,000 on your platform.
use delay(2L*1000*60) to calculate the value as long. as int the calculation overflows on 16bit int
It's an Arduino Uno, so that's an ATmega328P 16

标签： arduino arduino-uno arduino-ide arduino-c++

【解决方案1】：

dont do arithmetic operation on such function, why not just write delay(120000); instead?. if you want to make arithmetic operations, is better to separe the operation, like this:

long int timeDelay1 = 60*2*1000;
delay(timeDelay1);

such long delay is not very good practice, instead used the funtion millis() to measure time, like this:

    long int t0 = 0;
    long int t1 = 0;
    
    long int howManyTimeIWantToWait = 120000;
    
    void setup() {
      t0 = millis();  
    
    }
    
    void loop() {
      t1 = millis();
      if(t1 >= (t0+howManyTimeIWantToWait)){
        t0 = millis();
          //howManyTimeIWantToWait has been passed
      
      }
      //do other stuff whithout waiting on the function delay();
    }

【讨论】：