即使在数字读取不足之后，泵仍保持打开状态

Question

我是Arduino编程的初学者。下面脚本的目的是按下按钮开启按钮（d == 0）等待8秒钟关闭泵并发送短信警报。释放按钮后，泵保持关闭状态（紧急关闭）。

这里我设法在按下按钮时打开泵并发送消息。释放按钮后，泵成功关闭。然而，8秒后关闭泵的延迟并没有真正起作用，这让我感到困惑。相反，发生的是在8秒延迟之后泵立即猛拉（切换）然后继续保持开启并发送消息。我很感激任何见解。

// Include the GSM library
#include <GSM.h>
#define PINNUMBER ""

// initialize the library instance
GSM gsmAccess;
GSM_SMS sms;

int pinout = 3;
int ledout = 13;
int d=1;
int a = 1;

void setup() {
  pinMode(4,INPUT); // Input Power
  pinMode(pinout , OUTPUT); // Motor Output
  Serial.begin(9600);
  while (!Serial) {
    ; // wait for serial port to connect. Needed for native USB port only
  }

  Serial.println("SMS Messages Sender");

  // connection state
  boolean notConnected = true;

  // Start GSM shield
  // If your SIM has PIN, pass it as a parameter of begin() in quotes
  while (notConnected) {
    if (gsmAccess.begin(PINNUMBER) == GSM_READY) {
      notConnected = false;
    } else {
      Serial.println("Not connected");
      delay(1000);
    }
  }

  Serial.println("GSM initialized");
}

void loop() {
  d=digitalRead(4);
  // If digital state of pin 4 is zero start motor and power ON switch LED
  if(d==0){
  digitalWrite(pinout ,HIGH); 
  digitalWrite(ledout ,HIGH); 

  delay(8000); // This is the line that doesn't seem to work!
  digitalWrite(pinout ,LOW); // This is the line that doesn't seem to work!


  //for( a = 1; a < 2; a = a + 1 ){
  if (a<2){
  Serial.print("Enter a mobile number: ");
  char remoteNum[20] = "4xxxxxxx22"; 
  // sms text
  Serial.print("Now, enter SMS content: ");
  char txtMsg[200] = "Cow #57 SCC Abnormality Detected";
  //readSerial(txtMsg);
  Serial.println("SENDING");
  Serial.println();
  Serial.println("Message:");
  Serial.println(txtMsg);

  // send the message
  sms.beginSMS(remoteNum);
  sms.print(txtMsg);
  sms.endSMS();
  Serial.println("\nCOMPLETE!\n");
  }
  a = a+1;
  Serial.println(a);
  }else{
  digitalWrite(pinout ,LOW);
  digitalWrite(ledout ,LOW);
  a=1;
  }
   //Serial.print(d);  // Monitor state of Pin 4 
}