Watersource Controller

Project showcase

Components and supplies

Arduino Nano R3

Resistor 10k ohm

ElectroPeak 0.96" OLED 64x128 Display Module

any oled display will do, just see you make the right connections. A4 -> SDA A5 -> SCL

Relay Module (Generic)

this should be a common ground relay that switches when the pin is pulled low. Otherwise you have to change the code accordingly.

SparkFun Pushbutton switch 12mm

1N4007 – High Voltage, High Current Rated Diode

any diode will do, and they should be put on the solenoid valves. They are important to prevent causing resets of the arduino due to current spikes when the solenoids close again. The diode should be put so that they conduct electricity from GND to VCC. This is called a flyback diode setup.

Necessary tools and machines

Soldering iron (generic)

About this project

My project is about saving tap water, because people take water for granted but it really isn't. A lot of people flush the toilet with drinking water. That's just wrong. I'm using a pump to pump up ground water to flush the toilets. But this water can't be used to wash my clothes. That's why I put a 1000 liter storage tank in de backyard to collect rainwater. In this tank are 2 floating sensor. The bottom sensor when not floating will trigger the arduino to switch to tap water. When it's raining and the upper sensor is floating, the arduino will switch back to rainwater. Only when the washine machine is requesting water, the solenoid of the correct watersource will be openend. This is achieved by using a pressure sensor that is connected to the same pipe of where the washine machine is connected. There are two tresholds according to the watersource. This is because at my place the pressure of the waterpump is lower than the tap water pressure. There is also a switch you can connect (the upper connection on the picture). Here you can connect a switch, and when in the "on" possition, the watervalve of the correct source will be openen regardless of the pressure.

One thing that cost me a lot of trouble is the resetting of the arduino when the solenoids closed. It turned out to be the recoil of the solenoids. So it is very important to put fly-back diodes on the solenoids themselves. Therefore it is important to not switch polarity when you are connecting the wires that power the solenoid. Otherwise you will cause a short. So the diode should conduct from GND to VCC on the solenoids.

The finished circuit in temporary container (i know it doesn't look pretty :-) )

Code

codeArduino

#include <Wire.h>
#include <ACROBOTIC_SSD1306.h>

int Off = LOW;
int On = HIGH;

//initializing states
int WaterRelayState = On;
int PowerRelayState = On;
int MemoryState = Off;
int ServerState = 0;
int TSSourceCity = 0;
int TSSourceRain = 0;

//setting GPIO pins
const int ManualOverride = 8;
const int WaterSupplySwitch = 7;
const int PowerSupplySwitch = 6;
const int PressureSensor = A0;
const int BottomSensor = 4;
const int TopSensor = 5;

//pressure var
float CurrentPressure = 0;
float WaterPressureToggle = 0;
float WaterPressureToggleHIGH = 0;
float WaterPressureRef = 0;
int LowValue = 0;
int HighValue = 0;

boolean FLOW = false;
boolean RECALIBRATED = true;
boolean ManualFlow = false;

String Source = "";
String val = "";

//variables for delay without using delay
unsigned long CurrentMillis = 0;    // stores the value of millis() in each iteration of loop()
unsigned long PreviousMillis = 0;


//variable to protect against disconnected hose
unsigned long RunningWater = 0;

//constants
const long Interval = 1000;
//const long Interval_Wifi = 15000;
const int MaxWaterDuration = 300;
 
const int led = 13;



void calibrate(){
  CurrentPressure = analogRead(PressureSensor);
  WaterPressureRef = CurrentPressure;
  }

void setup(void) {
  Serial.begin(115200);
  pinMode(ManualOverride, INPUT);
  pinMode(WaterSupplySwitch, OUTPUT);
  pinMode(PowerSupplySwitch, OUTPUT);
  pinMode(BottomSensor, INPUT);
  pinMode(TopSensor, INPUT);
  pinMode(PressureSensor, INPUT);

  digitalWrite(PowerSupplySwitch, PowerRelayState);
  digitalWrite(WaterSupplySwitch, WaterRelayState);
  FLOW = true;
  //checkwaterlevel(1);
  delay(5000);
  FLOW = false;
  
  calibrate();
  
  Wire.begin();  
  oled.init();                      // Initialze SSD1306 OLED display
  oled.clearDisplay();              // clear screen
}

void loop(void) {

  CurrentMillis = millis();

  if(digitalRead(ManualOverride) == LOW){
    ManualFlow = true;}
    else{
    ManualFlow = false;
  }
  
  if(CurrentMillis - PreviousMillis >= Interval) {
      PreviousMillis = CurrentMillis; 
    CurrentPressure = analogRead(PressureSensor);
    Serial.print("CurrentPressure");
    Serial.println(CurrentPressure);
    checkwaterlevel(0);
    }
}

void sense(){
      WaterPressureToggle = ((100/WaterPressureRef)*CurrentPressure);
      if(Source == "Citywater"){LowValue = 85;HighValue = 90;}
      else{LowValue = 65;HighValue = 80;
      }      
      Serial.print("WaterPressureToggle");
        if(WaterPressureToggle < LowValue or ManualFlow == true){
          FLOW =  true;
        }
        else{
            if(WaterPressureToggle > HighValue){
            FLOW = false;
            WaterPressureToggleHIGH = WaterPressureToggle;
            }
          }
    }

void checkwaterlevel(int x) {
  Serial.print("Flow state = ");
  Serial.println(ManualFlow);
  /*if (RunningWater > MaxWaterDuration) {
    sensorfault();
  }*/

  if (x==0){sense();}

  if (FLOW or ManualFlow) {
    RECALIBRATED = false;
    PowerRelayState = On;
    RunningWater += (Interval / 1000);
    if (digitalRead(BottomSensor) == LOW and digitalRead(TopSensor) == LOW) {//LOW means sensor is floating
      WaterRelayState = On;
      MemoryState = WaterRelayState; 
      Source = "Rainwater";
      Serial.println("Bottomsensor and Topsensor closed, running on rainwater");
    }
    else{
      if(digitalRead(BottomSensor) == LOW){
        WaterRelayState = MemoryState;
        if(WaterRelayState == On){Source = "Rainwater";}
        else{Source = "Citywater";}
        }
      else{
        WaterRelayState = Off;
        MemoryState = WaterRelayState; 
        Source = "Citywater";
        Serial.println("Bottomsensor open, running on Pidpa");}
      }
  }
  else
  {
    if (RECALIBRATED == false) {calibrate();RECALIBRATED == true;}
    PowerRelayState = Off;
    WaterRelayState = Off;
    Source = "No power ";
    RunningWater = 0;
  }
  lcd();
  digitalWrite(PowerSupplySwitch, PowerRelayState);
  digitalWrite(WaterSupplySwitch, WaterRelayState);
  
}

void lcd() {
  oled.setTextXY(0, 0);             // Set cursor position, start of line 0
  oled.putString("Running on ");
  oled.setTextXY(1, 0);             // Set cursor position, start of line 1
  oled.putString(Source);
  oled.setTextXY(2,0);
  oled.putString("Top=");
  oled.setTextXY(2,4);
  if (digitalRead(TopSensor) == LOW){oled.putString("WET");}else{oled.putString("DRY");}
  oled.setTextXY(2,9);
  oled.putString("Bot=");
  oled.setTextXY(2,13);
  if (digitalRead(BottomSensor) == LOW){oled.putString("WET");}else{oled.putString("DRY");}
  
  oled.setTextXY(3, 0);
  oled.putString("LO ");
  oled.setTextXY(3,4);
  oled.putString("     ");
  oled.setTextXY(3,4);
  oled.putNumber(WaterPressureToggle);
  oled.setTextXY(3,9);
  oled.putString("HI ");
  oled.setTextXY(3,13);
  oled.putString("     ");
  oled.setTextXY(3,13);
  oled.putNumber(WaterPressureToggleHIGH);
  oled.setTextXY(4, 0);
  if (PowerRelayState == On)
  {
    oled.putString("valves opened");
  }
  else
  {
    oled.putString("valves closed");
  }
  oled.setTextXY(5, 0);
  val = digitalRead(WaterSupplySwitch);
  oled.putString("          ");
  oled.setTextXY(5, 0);
  oled.putString(val);
  oled.setTextXY(6, 0);
  oled.putString("    ");
  oled.setTextXY(6, 0);
  oled.putNumber(WaterPressureToggle);
}