Water Tank level display with Arduino

By on August 28, 2011

We present the candidature of Mr. Danilo Abbasciano that is proposed for the realization of the firmware for the TiDiGino project and that presents us an application with Arduino: Display the level of a tank.

The project reads and displays the height of water level in a well or a cistern.
We will use the open source Arduino hardware device, an ultrasonic Parallax sensor to measure the height of the water, a 16 x 2 LCD display with Hitachi HD44780 driver and a buzzer that is activated when the level exceeds the threshold.

The project, as we have already mentioned, is composed of several parts. A sonar sensor to be placed at the top of the well (at a safe distance from water level) that points downward so as to measure the distance between the point of placement (in our case the highest point of the well) and the surface water. Taking a simple difference between known quantities: the distance between the bottom and the measurement read from the sensor, we get the height of the water surface. Knowing the surface of the well also it is easy to calculate the volume of water present. At predetermined intervals Arduino reads the distances and displays the height and volume of water in the well.

There is a horizontal bar that shows the trend in relative water level inside the well for an easily and immediately read.


If the level exceeds a first threshold warning triggered the alarm buzzer to beep slowly if the level exceeds the second threshold, the ringing frequency increases until the level will drop back below the threshold or when you manually turn off the ringer through a button.

Arduino controls the operating logic, using the following sketches:

 

/* -*- mode: c -*- */
/**
 * pozzo.pde
 * version: 1.2
 */

#include <LiquidCrystal.h>

#define PING_PIN 13
#define BUZZER_PIN 8
#define SWITCH_INT 0 /* 0 => pin 2 */
#define PI 3.1415926535898
#define SUPERFICE_BASE (R_POZZO * R_POZZO * PI)
#define SIZE_BAR (16 * 5)
#define ALARM_ICON 0 /* code */
#define SOUND_ICON 6 /* code */
#define SOUND_ICON_ON 7 /* code */

#define R_POZZO 0.5 /* raggio pozzo (m) */
#define H_POZZO 146.0 /* cm */
#define SOGLIA_ALLARME_1 100 /* cm */
#define SOGLIA_ALLARME_2 120 /* cm */
#define DELAY_0 60000 /* ms; 1000 * 60 * 1 = 1 min */
#define DELAY_1 600 /* ms */
#define DELAY_2 200 /* ms */

/* initialize the library with the numbers of the interface pins */
LiquidCrystal lcd(12, 11, 5, 4, 3, 6);

int mute = 0;

byte *getChar(int n, byte newChar[]) {
  int i;
  byte code[5] = {
    B10000,
    B11000,
    B11100,
    B11110,
    B11111};

  for (i = 0; i < 8; i++)
    newChar[i] = code[n - 1];

  return newChar;
}

void setup() {
  int i;
  float h;
  byte newChar[8];

  /* set up the LCD's number of rows and columns: */
  lcd.begin(16, 2);

  for (i = 1; i < 6; i++)
    lcd.createChar(i, getChar(i, newChar));

  newChar = {
    B00000,
    B00100,
    B01010,
    B01010,
    B11111,
    B00100,
    B00000,
  };

  lcd.createChar(ALARM_ICON, newChar);

  newChar = {
    B00011,
    B00101,
    B11001,
    B11001,
    B11001,
    B00101,
    B00011,
  };

  lcd.createChar(SOUND_ICON, newChar);

  newChar = {
    B00100,
    B10010,
    B01001,
    B01001,
    B01001,
    B10010,
    B00100,
  };

  lcd.createChar(SOUND_ICON_ON, newChar);  

  pinMode(BUZZER_PIN, OUTPUT);

  /**
   * LOW to trigger the interrupt whenever the pin is low,
   * CHANGE to trigger the interrupt whenever the pin changes value
   * RISING to trigger when the pin goes from low to high,
   * FALLING for when the pin goes from high to low.
   */
  attachInterrupt(SWITCH_INT, button, RISING);

  /* initialize serial communication */
  Serial.begin(9600);
}

void loop() {
  long hWatherCm;
  int litres;

  hWatherCm = read_height();
  if (check_alarm(hWatherCm) != 0) /* read again wather height */
    hWatherCm = read_height();

  lcd.clear();

  print_histogram(hWatherCm);

  lcd.setCursor(0, 1);

  lcd.print(hWatherCm);
  lcd.print(" cm - ");

  // litres = SUPERFICE_BASE * (hWather / 100.0) * 1000
  litres = floor(SUPERFICE_BASE * hWatherCm * 10);
  lcd.print(litres);
  lcd.print(" l ");

  lcd.setCursor(14, 1);
  lcd.write(SOUND_ICON);
  lcd.setCursor(15, 1);
  if (!mute)
    lcd.write(SOUND_ICON_ON);
  else
    lcd.write('X');

/*
  Serial.print("cm = ");
  Serial.println(hWatherCm);
*/

  switch (check_alarm(hWatherCm)) {
  case 1:
    lcd.setCursor(0, 0);
    lcd.write(ALARM_ICON);

    buzz(200);
    delay(DELAY_1);
    break;

  case 2:
    lcd.setCursor(0, 0);
    lcd.write(ALARM_ICON);

    buzz(200);
    delay(200);
    buzz(200);
    delay(DELAY_2);
    break;

  case 0: // no alarm
    delay(DELAY_0);
  }
}

void print_histogram(int hWatherCm) {
  int i;
  int bloks;
  float histogram;

  // hWatherCm : HPOZZO = histogram : SIZE_BAR
  histogram = (SIZE_BAR * hWatherCm) / H_POZZO;
  histogram = histogram + 0.5;

  bloks = (int)histogram / 5;

  for (i = 0; i < bloks; i++)
    lcd.write(5);

  if ((int)(histogram) % 5 > 0)
    lcd.write((int)(histogram) % 5);
}

long read_height() {
  /**
   * establish variables for duration of the ping,
   * and the distance result in centimeters:
   */
  long duration, hWatherCm;

  /**
   * The PING))) is triggered by a HIGH pulse of 2 or more microseconds.
   * Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
   */
  pinMode(PING_PIN, OUTPUT);
  digitalWrite(PING_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(PING_PIN, HIGH);
  delayMicroseconds(5);
  digitalWrite(PING_PIN, LOW);

  /**
   * The same pin is used to read the signal from the PING))): a HIGH
   * pulse whose duration is the time (in microseconds) from the sending
   * of the ping to the reception of its echo off of an object.
   */
  pinMode(PING_PIN, INPUT);
  duration = pulseIn(PING_PIN, HIGH);

  /* convert the time into a distance */
  hWatherCm = H_POZZO - microseconds_to_centimeters(duration);

  if (hWatherCm < 0)
    return 0;

  if (hWatherCm > H_POZZO)
    return H_POZZO;

  return hWatherCm;
}

void buzz(int msec) {
  if (!mute)
    digitalWrite(BUZZER_PIN, HIGH);
  delay(msec);
  digitalWrite(BUZZER_PIN, LOW);
}

int check_alarm(int hWatherCm) {
  if (hWatherCm > SOGLIA_ALLARME_1) {
     if (hWatherCm < SOGLIA_ALLARME_2)
       return 1;
     else
       return 2;
  }
  return 0;
}

long microseconds_to_centimeters(long microseconds) {
  /**
   * The speed of sound is 340.29 m/s or 29.4 microseconds per centimeter.
   * The ping travels out and back, so to find the distance of the
   * object we take half of the distance travelled.
   */
  return microseconds / 29.387 / 2;
}

void button() {
  //  Serial.println("Pulsante premuto");
  mute = !mute;

  lcd.setCursor(15, 1);
  if (!mute)
    lcd.write(SOUND_ICON_ON);
  else
    lcd.write('X');
}

About Boris Landoni

Boris Landoni is the technical manager of Open-Electronics.org. Skilled in the GSM field, embraces the Open Source philosophy and its projects are available to the community.
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  • Stefan

    Hello, where can I get a list of the used components? Are they provided by the open-electronics-store?

  • Hi, this is a idea of project, we don’t sell all the componenti but only the Arduino UNO http://store.open-electronics.org/ArduinoUNOR3

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  • rojalin

    please give details of this project

  • Michel Doffagne

    whaow. You are ahead on my project. I want to do similar, but I was wondering about the humidity protection of the ultrasonic detector. Did you do something special ? Nice job.

  • Pingback: Water Tank level display with Arduino | Arduino in the Classroom | Scoop.it()

  • joseph

    can i see the components and and the architectural design of this?

  • emil

    what is the minimum measurement level?

  • vedang joshi

    Hey, I am impressed by your project. I am sure that i would try my hand on it but as i am a beginner i don’t know how to write codes. So, i request you to please help me with the code. You can also email me the code at vedangj044@gmail.com Please

    • Garry Brook

      Where do I find the schematic for this?

  • shali

    youa progrmmer not working

    • HASHIM ASHRAF

      its the working program
      Regards Hashim,Ashraf -(* – *)-

      #include
      #define PING_PIN 13

      #define BUZZER_PIN 8

      #define SWITCH_INT 0 /* 0 => pin 2 */

      #define PI 3.1415926535898

      #define SUPERFICE_BASE (R_POZZO * R_POZZO * PI)

      #define SIZE_BAR (16 * 5)

      #define ALARM_ICON 0 /* code */

      #define SOUND_ICON 6 /* code */

      #define SOUND_ICON_ON 7 /* code */

      #define R_POZZO 0.5 /* raggio pozzo (m) */

      #define H_POZZO 146.0 /* cm */

      #define SOGLIA_ALLARME_1 100 /* cm */

      #define SOGLIA_ALLARME_2 120 /* cm */

      #define DELAY_0 60000 /* ms; 1000 * 60 * 1 = 1 min */

      #define DELAY_1 600 /* ms */

      #define DELAY_2 200 /* ms */

      /* initialize the library with the numbers of the interface pins */

      LiquidCrystal lcd(12, 11, 5, 4, 3, 6);

      int mute = 0;

      byte *getChar(int n, byte newChar[]) {

      int i;

      byte code[5] = {

      B10000,

      B11000,

      B11100,

      B11110,

      B11111};

      for (i = 0; i < 8; i++)

      newChar[i] = code[n – 1];

      return newChar;

      }

      void setup() {

      int i;

      float h;

      byte newChar[8];

      /* set up the LCD's number of rows and columns: */

      lcd.begin(16, 2);

      for (i = 1; i < 6; i++)

      lcd.createChar(i, getChar(i, newChar));

      {

      newChar[0] =B00000;

      newChar[1] =B00100;

      newChar[2] =B01010;

      newChar[3] =B01010;

      newChar[4] =B11111;

      newChar[5] =B00100;

      newChar[6] =B00000;

      }

      lcd.createChar(ALARM_ICON, newChar);

      {

      newChar[0] =B00011;

      newChar[1] =B00101;

      newChar[2] =B11001;

      newChar[3] =B11001;

      newChar[4] =B11001;

      newChar[5] =B00101;

      newChar[6] =B00011;

      }

      lcd.createChar(SOUND_ICON, newChar);

      {

      newChar[0] =B00100;

      newChar[1] =B10010;

      newChar[2] =B01001;

      newChar[3] =B01001;

      newChar[4] =B01001;

      newChar[5] =B10010;

      newChar[6] =B00100;

      }

      lcd.createChar(SOUND_ICON_ON, newChar);

      pinMode(BUZZER_PIN, OUTPUT);

      /**

      * LOW to trigger the interrupt whenever the pin is low,

      * CHANGE to trigger the interrupt whenever the pin changes value

      * RISING to trigger when the pin goes from low to high,

      * FALLING for when the pin goes from high to low.

      */

      attachInterrupt(digitalPinToInterrupt(SWITCH_INT), button, RISING);

      /* initialize serial communication */

      Serial.begin(9600);

      }

      void loop() {

      long hWatherCm;

      int litres;

      hWatherCm = read_height();

      if (check_alarm(hWatherCm) != 0) /* read again wather height */

      hWatherCm = read_height();

      lcd.clear();

      print_histogram(hWatherCm);

      lcd.setCursor(0, 1);

      lcd.print(hWatherCm);

      lcd.print(" cm – ");

      // litres = SUPERFICE_BASE * (hWather / 100.0) * 1000

      litres = floor(SUPERFICE_BASE * hWatherCm * 10);

      lcd.print(litres);

      lcd.print(" l ");

      lcd.setCursor(14, 1);

      lcd.write(SOUND_ICON);

      lcd.setCursor(15, 1);

      if (!mute)

      lcd.write(SOUND_ICON_ON);

      else

      lcd.write('X');

      /*

      Serial.print("cm = ");

      Serial.println(hWatherCm);

      */

      switch (check_alarm(hWatherCm)) {

      case 1:

      lcd.setCursor(0, 0);

      //lcd.write("A,N");

      buzz(200);

      delay(DELAY_1);

      break;

      case 2:

      lcd.setCursor(0, 0);

      // lcd.write("A,N");

      buzz(200);

      delay(200);

      buzz(200);

      delay(DELAY_2);

      break;

      case 0: // no alarm

      delay(DELAY_0);

      }

      }

      void print_histogram(int hWatherCm) {

      int i;

      int bloks;

      float histogram;

      // hWatherCm : HPOZZO = histogram : SIZE_BAR

      histogram = (SIZE_BAR * hWatherCm) / H_POZZO;

      histogram = histogram + 0.5;

      bloks = (int)histogram / 5;

      for (i = 0; i 0)

      lcd.write((int)(histogram) % 5);

      }

      long read_height() {

      /**

      * establish variables for duration of the ping,

      * and the distance result in centimeters:

      */

      long duration, hWatherCm;

      /**

      * The PING))) is triggered by a HIGH pulse of 2 or more microseconds.

      * Give a short LOW pulse beforehand to ensure a clean HIGH pulse:

      */

      pinMode(PING_PIN, OUTPUT);

      digitalWrite(PING_PIN, LOW);

      delayMicroseconds(2);

      digitalWrite(PING_PIN, HIGH);

      delayMicroseconds(5);

      digitalWrite(PING_PIN, LOW);

      /**

      * The same pin is used to read the signal from the PING))): a HIGH

      * pulse whose duration is the time (in microseconds) from the sending

      * of the ping to the reception of its echo off of an object.

      */

      pinMode(PING_PIN, INPUT);

      duration = pulseIn(PING_PIN, HIGH);

      /* convert the time into a distance */

      hWatherCm = H_POZZO – microseconds_to_centimeters(duration);

      if (hWatherCm H_POZZO)

      return H_POZZO;

      return hWatherCm;

      }

      void buzz(int msec) {

      if (!mute)

      digitalWrite(BUZZER_PIN, HIGH);

      delay(msec);

      digitalWrite(BUZZER_PIN, LOW);

      }

      int check_alarm(int hWatherCm) {

      if (hWatherCm > SOGLIA_ALLARME_1) {

      if (hWatherCm < SOGLIA_ALLARME_2)

      return 1;

      else

      return 2;

      }

      return 0;

      }

      long microseconds_to_centimeters(long microseconds) {

      /**

      * The speed of sound is 340.29 m/s or 29.4 microseconds per centimeter.

      * The ping travels out and back, so to find the distance of the

      * object we take half of the distance travelled.

      */

      return microseconds / 29.387 / 2;

      }

      void button() {

      mute = !mute;

      lcd.setCursor(15, 1);

      if(!mute)

      lcd.write(SOUND_ICON_ON);

      else

      lcd.write('X');

      }

  • Davide

    Dear all, I’m trying to assembly one project that §I found on internet, but I have found a few trouble when I have tested it. So, on the display strange characters appear (no number, icon…etc), the sensor doesn’t read the distance. I already checked the connection and with multimeter everything is ok, could be possible the sketchbook is wrong? So my question if is there is somebody can help me to solve this trouble.

  • Anthony

    hello I am new to Arduino, I copied and pasted the code but I get an error when compiling, please help

  • Anthony

    when I copy and paste I have this compiling errors:

    Arduino: 1.7.6 (Windows 10), Board: “Arduino Uno”

    LCD_Tank_Level_Meter.ino: In function ‘void setup()’:

    LCD_Tank_Level_Meter.ino:58:11: error: assigning to an array from an initializer list

    LCD_Tank_Level_Meter.ino:70:11: error: assigning to an array from an initializer list

    LCD_Tank_Level_Meter.ino:82:11: error: assigning to an array from an initializer list

    LCD_Tank_Level_Meter.ino: In function ‘void loop()’:

    LCD_Tank_Level_Meter.ino:146:25: error: call of overloaded ‘write(int)’ is ambiguous

    LCD_Tank_Level_Meter.ino:146:25: note: candidates are:

    In file included from LCD_Tank_Level_Meter.ino:7:0:

    D:ArduinolibrariesLiquidCrystalsrc/LiquidCrystal.h:83:18: note: virtual size_t LiquidCrystal::write(uint8_t)

    virtual size_t write(uint8_t);

    ^

    In file included from D:ArduinolibrariesLiquidCrystalsrc/LiquidCrystal.h:5:0,

    from LCD_Tank_Level_Meter.ino:7:

    D:Arduinohardwarearduinoavrcoresarduino/Print.h:49:12: note: size_t Print::write(const char*)

    size_t write(const char *str) {

    ^

    LCD_Tank_Level_Meter.ino:154:25: error: call of overloaded ‘write(int)’ is ambiguous

    LCD_Tank_Level_Meter.ino:154:25: note: candidates are:

    In file included from LCD_Tank_Level_Meter.ino:7:0:

    D:ArduinolibrariesLiquidCrystalsrc/LiquidCrystal.h:83:18: note: virtual size_t LiquidCrystal::write(uint8_t)

    virtual size_t write(uint8_t);

    ^

    In file included from D:ArduinolibrariesLiquidCrystalsrc/LiquidCrystal.h:5:0,

    from LCD_Tank_Level_Meter.ino:7:

    D:Arduinohardwarearduinoavrcoresarduino/Print.h:49:12: note: size_t Print::write(const char*)

    size_t write(const char *str) {

    ^

    Error compiling.

  • Kami Reddy Thejesh

    Hi, I too doing on the Same type of Project .
    But need to read the Data Measured on the Tank And So As to control the Flow, Using a Flow Meter .
    My Project needs to be Continued From the Point of Reading the data .
    Any one Please Suggest, How to read the values .

  • joe conery

    I made something along these lines awhile back for the sump of my saltwater aquarium. Eventually evaporation/humidity/salt splashing… interfered with it’s ability to function.
    The beam is not that focused, so you need to put it fairly close to the water surface so that it doesn’t read the top edges of your container where it becomes susceptible to this.

  • HASHIM ASHRAF

    Thanks Boris Landoni for this awsome -(* – *)-

    i figured out some mistakes on your pgm

    Its the final one;

    #include

    #define PING_PIN 13

    #define BUZZER_PIN 8

    #define SWITCH_INT 0 /* 0 => pin 2 */

    #define PI 3.1415926535898

    #define SUPERFICE_BASE (R_POZZO * R_POZZO * PI)

    #define SIZE_BAR (16 * 5)

    #define ALARM_ICON 0 /* code */

    #define SOUND_ICON 6 /* code */

    #define SOUND_ICON_ON 7 /* code */

    #define R_POZZO 0.5 /* raggio pozzo (m) */

    #define H_POZZO 146.0 /* cm */

    #define SOGLIA_ALLARME_1 100 /* cm */

    #define SOGLIA_ALLARME_2 120 /* cm */

    #define DELAY_0 60000 /* ms; 1000 * 60 * 1 = 1 min */

    #define DELAY_1 600 /* ms */

    #define DELAY_2 200 /* ms */

    /* initialize the library with the numbers of the interface pins */

    LiquidCrystal lcd(12, 11, 5, 4, 3, 6);

    int mute = 0;

    byte *getChar(int n, byte newChar[]) {

    int i;

    byte code[5] = {

    B10000,

    B11000,

    B11100,

    B11110,

    B11111};

    for (i = 0; i < 8; i++)

    newChar[i] = code[n – 1];

    return newChar;

    }

    void setup() {

    int i;

    float h;

    byte newChar[8];

    /* set up the LCD's number of rows and columns: */

    lcd.begin(16, 2);

    for (i = 1; i < 6; i++)

    lcd.createChar(i, getChar(i, newChar));

    {

    newChar[0] =B00000;

    newChar[1] =B00100;

    newChar[2] =B01010;

    newChar[3] =B01010;

    newChar[4] =B11111;

    newChar[5] =B00100;

    newChar[6] =B00000;

    }

    lcd.createChar(ALARM_ICON, newChar);

    {

    newChar[0] =B00011;

    newChar[1] =B00101;

    newChar[2] =B11001;

    newChar[3] =B11001;

    newChar[4] =B11001;

    newChar[5] =B00101;

    newChar[6] =B00011;

    }

    lcd.createChar(SOUND_ICON, newChar);

    {

    newChar[0] =B00100;

    newChar[1] =B10010;

    newChar[2] =B01001;

    newChar[3] =B01001;

    newChar[4] =B01001;

    newChar[5] =B10010;

    newChar[6] =B00100;

    }

    lcd.createChar(SOUND_ICON_ON, newChar);

    pinMode(BUZZER_PIN, OUTPUT);

    /**

    * LOW to trigger the interrupt whenever the pin is low,

    * CHANGE to trigger the interrupt whenever the pin changes value

    * RISING to trigger when the pin goes from low to high,

    * FALLING for when the pin goes from high to low.

    */

    attachInterrupt(digitalPinToInterrupt(SWITCH_INT), button, RISING);

    /* initialize serial communication */

    Serial.begin(9600);

    }

    void loop() {

    long hWatherCm;

    int litres;

    hWatherCm = read_height();

    if (check_alarm(hWatherCm) != 0) /* read again wather height */

    hWatherCm = read_height();

    lcd.clear();

    print_histogram(hWatherCm);

    lcd.setCursor(0, 1);

    lcd.print(hWatherCm);

    lcd.print(" cm – ");

    // litres = SUPERFICE_BASE * (hWather / 100.0) * 1000

    litres = floor(SUPERFICE_BASE * hWatherCm * 10);

    lcd.print(litres);

    lcd.print(" l ");

    lcd.setCursor(14, 1);

    lcd.write(SOUND_ICON);

    lcd.setCursor(15, 1);

    if (!mute)

    lcd.write(SOUND_ICON_ON);

    else

    lcd.write('X');

    /*

    Serial.print("cm = ");

    Serial.println(hWatherCm);

    */

    switch (check_alarm(hWatherCm)) {

    case 1:

    lcd.setCursor(0, 0);

    //lcd.write("A,N");

    buzz(200);

    delay(DELAY_1);

    break;

    case 2:

    lcd.setCursor(0, 0);

    // lcd.write("A,N");

    buzz(200);

    delay(200);

    buzz(200);

    delay(DELAY_2);

    break;

    case 0: // no alarm

    delay(DELAY_0);

    }

    }

    void print_histogram(int hWatherCm) {

    int i;

    int bloks;

    float histogram;

    // hWatherCm : HPOZZO = histogram : SIZE_BAR

    histogram = (SIZE_BAR * hWatherCm) / H_POZZO;

    histogram = histogram + 0.5;

    bloks = (int)histogram / 5;

    for (i = 0; i 0)

    lcd.write((int)(histogram) % 5);

    }

    long read_height() {

    /**

    * establish variables for duration of the ping,

    * and the distance result in centimeters:

    */

    long duration, hWatherCm;

    /**

    * The PING))) is triggered by a HIGH pulse of 2 or more microseconds.

    * Give a short LOW pulse beforehand to ensure a clean HIGH pulse:

    */

    pinMode(PING_PIN, OUTPUT);

    digitalWrite(PING_PIN, LOW);

    delayMicroseconds(2);

    digitalWrite(PING_PIN, HIGH);

    delayMicroseconds(5);

    digitalWrite(PING_PIN, LOW);

    /**

    * The same pin is used to read the signal from the PING))): a HIGH

    * pulse whose duration is the time (in microseconds) from the sending

    * of the ping to the reception of its echo off of an object.

    */

    pinMode(PING_PIN, INPUT);

    duration = pulseIn(PING_PIN, HIGH);

    /* convert the time into a distance */

    hWatherCm = H_POZZO – microseconds_to_centimeters(duration);

    if (hWatherCm H_POZZO)

    return H_POZZO;

    return hWatherCm;

    }

    void buzz(int msec) {

    if (!mute)

    digitalWrite(BUZZER_PIN, HIGH);

    delay(msec);

    digitalWrite(BUZZER_PIN, LOW);

    }

    int check_alarm(int hWatherCm) {

    if (hWatherCm > SOGLIA_ALLARME_1) {

    if (hWatherCm < SOGLIA_ALLARME_2)

    return 1;

    else

    return 2;

    }

    return 0;

    }

    long microseconds_to_centimeters(long microseconds) {

    /**

    * The speed of sound is 340.29 m/s or 29.4 microseconds per centimeter.

    * The ping travels out and back, so to find the distance of the

    * object we take half of the distance travelled.

    */

    return microseconds / 29.387 / 2;

    }

    void button() {

    mute = !mute;

    lcd.setCursor(15, 1);

    if(!mute)

    lcd.write(SOUND_ICON_ON);

    else

    lcd.write('X');

    }

  • Jon Biddell

    I know this is old, but I’m going to get my daughter to build this as a learning experience… Just wondering if it would be possible to incorporate a flow sensor in it as well ??

    • BorisLandoni

      HI, this is open source, of course you can modify it to insert new features 😉