How to stop when reached maximum?

Using Arduino Programming Questions
1

Hi everyone, This is the first time for me to use an arduino. I am doing a small project on making a some sort of data logger, which will be measuring voltage and current with varies load resistance and calculate the power. I have been wondering around the internet, but it seems that the resources can't resolve my problem.

    while(inByte=='s'){
      analogWrite(lampPin, 191);
      Measurement();
      digitalWrite(rledPin, LOW);
      digitalWrite(gledPin, HIGH);
    }
  }
}

void Measurement() {
  int VoltageSensor = analogRead(A0);
  int CurrentSensor = analogRead(A1);
  float voltage = VoltageSensor* (5.0 / 1023.0);
  float current = CurrentSensor* (5.0 / 153603.5);
  float power = voltage* current;
  Serial.print(voltage, 5);
  Serial.print('\t');
  Serial.print(current, 5);
  Serial.print('\t');
  Serial.print(power, 5);
  Serial.println();
  delay(1000);
}

How do I tell arduino stop when the maximum power is reached?
My idea is like :

  1. if nowPower>prevPower, keep reading
  2. if prevPower>nowPower, stop reading, prevPower=maxPower
  3. Serial.print(maxPower)

Not sure how to do it exactly, and one last thing, in my sketch when I press 's' in the monitor, it will start measuring, the problem is I don't know how to break the while loop, I have tried to use delay and break, they didn't seem to work, maybe I have done something wrong.

Please help

2

The first thing to do is to post your whole program, not just the bit(s) that you think are important

3

My idea is like :

  1. if nowPower>prevPower, keep reading
  2. if prevPower>nowPower, stop reading, prevPower=maxPower
  3. Serial.print(maxPower)

Step 1 should be:

  1. if nowPower>prevPower, set prevPower = nowPower, keep reading

Step 2 should be more like:
2) if prevPower>nowPower, maxPower=prevPower, stop reading

I don't know why break wouldn't exit the loop, It should have; I suspect it did, but you have another infinite loop surrounding it. Do you really want a while loop? Another way to exit the loop that is more conventional is to make sure the condition (inByte == 's') becomes non-true at some point. I would have expected inByte to change at some point causing the loop to terminate normally.