Fix Water Level Sensor Accuracy NOW!

1int sensorval = 0;  // holds the value
2int sensorpin = A0; // sensor pin used  
3
4void setup() { 
5  
6  Serial.begin(9600);
7  pinMode(sensorpin, INPUT);
8} 
9
10void loop() { 
11  sensorval = analogRead(sensorpin);
12  
13  if (sensorval<=200)
14  { 
15      Serial.println("Water Level: Empty"); 
16    }
17
18    else if (sensorval>=200 && sensorval<=450)
19    {
20      Serial.println("Water Level: Low"); 
21      }
22
23      else if (sensorval>=450 && sensorval<=620)
24      {
25        Serial.println("Water Level: Medium");
26        }
27        else if (sensorval>620)
28
29        {
30        Serial.println("Water Level: High"); 
31        } 
32       delay(1000);
33        }

1/*
2  Analog input, analog output, serial output
3
4  Reads an analog input pin, maps the result to a range from 0 to 255 and uses
5  the result to set the pulse width modulation (PWM) of an output pin.
6  Also prints the results to the Serial Monitor.
7
8  The circuit:
9  - potentiometer connected to analog pin 0.
10    Center pin of the potentiometer goes to the analog pin.
11    side pins of the potentiometer go to +5V and ground
12  - LED connected from digital pin 9 to ground through 220 ohm resistor
13
14  created 29 Dec. 2008
15  modified 9 Apr 2012
16  by Tom Igoe
17
18  This example code is in the public domain.
19
20  https://www.arduino.cc/en/Tutorial/BuiltInExamples/AnalogInOutSerial
21*/
22
23// These constants won't change. They're used to give names to the pins used:
24const int analogInPin = A0;  // Analog input pin that the potentiometer is attached to
25const int analogOutPin = 9; // Analog output pin that the LED is attached to
26
27int sensorValue = 0;        // value read from the pot
28int outputValue = 0;        // value output to the PWM (analog out)
29
30void setup() {
31  // initialize serial communications at 9600 bps:
32  Serial.begin(9600);
33}
34
35void loop() {
36  // read the analog in value:
37  sensorValue = analogRead(analogInPin);
38  // map it to the range of the analog out:
39  outputValue = map(sensorValue, 0, 1023, 0, 255);
40  // change the analog out value:
41  analogWrite(analogOutPin, outputValue);
42
43  // print the results to the Serial Monitor:
44  Serial.print("sensor = ");
45  Serial.print(sensorValue);
46  Serial.print("\t output = ");
47  Serial.println(outputValue);
48
49  // wait 2 milliseconds before the next loop for the analog-to-digital
50  // converter to settle after the last reading:
51  delay(2);
52}