Non-blocking analogRead

Question

In my recent project, I'm working with the motor. I have to drive the motor for the specific time like for 2 minutes, 3 minutes, 4 minutes and 5 minutes. I already created functions for that. And motor drive based on readings taken from the sensor.

My code is below:

#define PIN_OUTPUT 6

const int kPinIN1 = 4;
const int kPinIN2 = 5;

void setup()
{
  Serial.begin(9600);

  pinMode(kPinIN1, OUTPUT);
  pinMode(kPinIN2, OUTPUT);
}

void loop() 
{
  Serial.println(analogRead(A0));

  if(analogRead(A0) > 100 && analogRead(A0) < 200)
  {
    motorDriveFor2Min();
  }
  else if(analogRead(A0) > 200 && analogRead(A0) < 300)
  {
    motorDriveFor3Min();
  }
  else if(analogRead(A0) > 300 && analogRead(A0) < 400)
  {
    motorDriveFor4Min();
  }
  else if(analogRead(A0) > 400 && analogRead(A0) < 500)
  {
    motorDriveFor5Min();
  }      
}

void motorDriveFor2Min()
{
  digitalWrite(kPinIN1, HIGH);
  digitalWrite(kPinIN2, LOW);

  analogWrite(PIN_OUTPUT, 255);

  verboseDelay(7000);

  digitalWrite(kPinIN1, LOW);
  digitalWrite(kPinIN2, HIGH);

  analogWrite(PIN_OUTPUT, 255);

  verboseDelay(7000);

  digitalWrite(kPinIN1, HIGH);
  digitalWrite(kPinIN2, LOW);

  analogWrite(PIN_OUTPUT, 255);

  verboseDelay(7000);

  digitalWrite(kPinIN1, LOW);
  digitalWrite(kPinIN2, HIGH);

  analogWrite(PIN_OUTPUT, 255);

  verboseDelay(7000);

  digitalWrite(kPinIN1, HIGH);
  digitalWrite(kPinIN2, LOW);

  analogWrite(PIN_OUTPUT, 255);

  verboseDelay(7000);

  digitalWrite(kPinIN1, LOW);
  digitalWrite(kPinIN2, HIGH);

  analogWrite(PIN_OUTPUT, 255);

  verboseDelay(7000);

  digitalWrite(kPinIN1, HIGH);
  digitalWrite(kPinIN2, LOW);

  analogWrite(PIN_OUTPUT, 255);

  verboseDelay(7000);

  digitalWrite(kPinIN1, LOW);
  digitalWrite(kPinIN2, HIGH);

  analogWrite(PIN_OUTPUT, 255);

  verboseDelay(7000);            

  digitalWrite(kPinIN1, HIGH);
  digitalWrite(kPinIN2, LOW);

  analogWrite(PIN_OUTPUT, 255);

  verboseDelay(64000);  
}


void motorDriveFor3Min()
{
  motorDriveFor2Min();

  digitalWrite(kPinIN1, HIGH);
  digitalWrite(kPinIN2, LOW);

  analogWrite(PIN_OUTPUT, 255);

  verboseDelay(7000);

  digitalWrite(kPinIN1, LOW);
  digitalWrite(kPinIN2, HIGH);

  analogWrite(PIN_OUTPUT, 255);

  verboseDelay(7000);

  digitalWrite(kPinIN1, HIGH);
  digitalWrite(kPinIN2, LOW);

  analogWrite(PIN_OUTPUT, 255);

  verboseDelay(7000);

  digitalWrite(kPinIN1, LOW);
  digitalWrite(kPinIN2, HIGH);

  analogWrite(PIN_OUTPUT, 255);

  verboseDelay(7000);

  digitalWrite(kPinIN1, HIGH);
  digitalWrite(kPinIN2, LOW);

  analogWrite(PIN_OUTPUT, 255);

  verboseDelay(32000);  
}

void motorDriveFor4Min()
{
  motorDriveFor3Min();

  digitalWrite(kPinIN1, HIGH);
  digitalWrite(kPinIN2, LOW);

  analogWrite(PIN_OUTPUT, 255);

  verboseDelay(7000);

  digitalWrite(kPinIN1, LOW);
  digitalWrite(kPinIN2, HIGH);

  analogWrite(PIN_OUTPUT, 255);

  verboseDelay(7000);

  digitalWrite(kPinIN1, HIGH);
  digitalWrite(kPinIN2, LOW);

  analogWrite(PIN_OUTPUT, 255);

  verboseDelay(46000);   
}

void motorDriveFor5Min()
{
  digitalWrite(kPinIN1, HIGH);
  digitalWrite(kPinIN2, LOW);

  analogWrite(PIN_OUTPUT, 255);

  verboseDelay(120000);

  digitalWrite(kPinIN1, HIGH);
  digitalWrite(kPinIN2, LOW);

  analogWrite(PIN_OUTPUT, 255);

  verboseDelay(7000);

  digitalWrite(kPinIN1, LOW);
  digitalWrite(kPinIN2, HIGH);

  analogWrite(PIN_OUTPUT, 255);

  verboseDelay(7000);

  digitalWrite(kPinIN1, HIGH);
  digitalWrite(kPinIN2, LOW);

  analogWrite(PIN_OUTPUT, 255);

  verboseDelay(7000);

  digitalWrite(kPinIN1, LOW);
  digitalWrite(kPinIN2, HIGH);

  analogWrite(PIN_OUTPUT, 255);

  verboseDelay(7000);

  digitalWrite(kPinIN1, HIGH);
  digitalWrite(kPinIN2, LOW);

  analogWrite(PIN_OUTPUT, 255);

  verboseDelay(7000);

  digitalWrite(kPinIN1, LOW);
  digitalWrite(kPinIN2, HIGH);

  analogWrite(PIN_OUTPUT, 255);

  verboseDelay(7000);

  digitalWrite(kPinIN1, HIGH);
  digitalWrite(kPinIN2, LOW);

  analogWrite(PIN_OUTPUT, 255);

  verboseDelay(7000);

  digitalWrite(kPinIN1, LOW);
  digitalWrite(kPinIN2, HIGH);

  analogWrite(PIN_OUTPUT, 255);

  verboseDelay(7000);

  digitalWrite(kPinIN1, LOW);
  digitalWrite(kPinIN2, HIGH);

  analogWrite(PIN_OUTPUT, 255);

  verboseDelay(120000);
}

void verboseDelay(unsigned long ms)
{
  unsigned long now = millis();
  unsigned long start = now;

  do
  {
    now = millis();
  }
  while (now - start < ms);
}

Here, I have four functions named motorDriveFor2Min(), motorDriveFor3Min(), motorDriveFor4Min() and motorDriveFor5Min() for my specific time means for 2 minutes, 3 minutes, 4 minutes and 5 minutes respectively.

So, suppose If I want to drive motor for 4 min then I have to call function motorDriveFor4Min() and for that, I have to set my reading between 300 & 400. But I can't able to do that because when my reading reaches at 100 then it starts executing another function means motorDriveFor2Min() and then continuously run that functionality. During that time I try to change the reading but nothing happens. After restating Arduino it run according to the reading.

So, I thought maybe delay() function block everything. So I replace inbuilt delay function with custom delay function. But that can't solve my problem. Then I google it out and I found out that analogRead may cause this problem. Any suggestion for this.

Answer 1

It's not analogRead. It's not (just) delay. It's the whole method of your program.

The way it's written you can do nothing else while driving a motor for X minutes.

You need to rethink your whole program so that it's not "run for X minutes" each time, but instead "Run the motor until the time is up" and constantly re-evaluate what the time should be.

That means:

• No "run for X" functions.
• No delay() functions (of any form - yours is as bad as the normal one).
• A state machine to determine what should be happening when.
• Constantly referencing both millis() and analogRead() to determine what state the state machine should be in or progress to and when.