Water Quality Module

With this compact device, all you have to do to acquire the water quality information of any water source is drop it in!

AdvancedWork in progressOver 1 day233

Things used in this project

Hardware components

Particle Argon

Waterproof Temperature Sensor

pH Sensor

TDS Meter Sensor

Software apps and online services

Particle Build Web IDE

Hand tools and fabrication machines

Creality CR-10s 3D Printer

Story

Since the beginning of time, man has been plagued with unsanitary drinking water. Such conditions have led to many illnesses, such as Cholera, E Coli, and Dysentery. Many people have tried to combat these illnesses through various processes: Distillation, Reverse Osmosis, and Electrodialysis. While these are effective techniques, they do take time to provide clean drinking water for human consumption. Not to mention, the water itself could be tainted with radiation or chemicals. That's where we come in! Our new Water Quality Sensor can analyze water in a shorter period of time and even deduce the temperature and pH levels of said water. The device utilizes particle argon technology to send data from the sensors to your device to let you know if the water is safe to drink or not.

Schematics

Code

#define TdsSensorPin A1
#define VREF 3.3      // analog reference voltage(Volt) of the ADC
#define SCOUNT  30           // sum of sample point
int analogBuffer[SCOUNT];    // store the analog value in the array, read from ADC
int analogBufferTemp[SCOUNT];
int analogBufferIndex = 0,copyIndex = 0;
float averageVoltage = 0,tdsValue = 0,temperature = 25;

void setup()
{
    Serial.begin(115200);
    pinMode(TdsSensorPin,INPUT);
}

void loop()
{
   static unsigned long analogSampleTimepoint = millis();
   if(millis()-analogSampleTimepoint > 40U)     //every 40 milliseconds,read the analog value from the ADC
   {
     analogSampleTimepoint = millis();
     analogBuffer[analogBufferIndex] = analogRead(TdsSensorPin);    //read the analog value and store into the buffer
     analogBufferIndex++;
     if(analogBufferIndex == SCOUNT) 
         analogBufferIndex = 0;
   }   
   static unsigned long printTimepoint = millis();
   if(millis()-printTimepoint > 800U)
   {
      printTimepoint = millis();
      for(copyIndex=0;copyIndex<SCOUNT;copyIndex++)
        analogBufferTemp[copyIndex]= analogBuffer[copyIndex];
      averageVoltage = getMedianNum(analogBufferTemp,SCOUNT) * (float)VREF / 1024.0; // read the analog value more stable by the median filtering algorithm, and convert to voltage value
      float compensationCoefficient=1.0+0.02*(temperature-25.0);    //temperature compensation formula: fFinalResult(25^C) = fFinalResult(current)/(1.0+0.02*(fTP-25.0));
      float compensationVolatge=averageVoltage/compensationCoefficient;  //temperature compensation
      tdsValue=(133.42*compensationVolatge*compensationVolatge*compensationVolatge - 255.86*compensationVolatge*compensationVolatge + 857.39*compensationVolatge)*0.5;
      Particle.publish("TDS Value:");
      Serial.print(tdsValue,0);
      Serial.println("ppm");
   }
}
int getMedianNum(int bArray[], int iFilterLen) 
{
      int bTab[iFilterLen];
      for (byte i = 0; i<iFilterLen; i++)
      bTab[i] = bArray[i];
      int i, j, bTemp;
      for (j = 0; j < iFilterLen - 1; j++) 
      {
      for (i = 0; i < iFilterLen - j - 1; i++) 
          {
        if (bTab[i] > bTab[i + 1]) 
            {
        bTemp = bTab[i];
            bTab[i] = bTab[i + 1];
        bTab[i + 1] = bTemp;
         }
      }
      }
      if ((iFilterLen & 1) > 0)
    bTemp = bTab[(iFilterLen - 1) / 2];
      else
    bTemp = (bTab[iFilterLen / 2] + bTab[iFilterLen / 2 - 1]) / 2;
      return bTemp;
}

#include <OneWire.h>
#include <DS18.h>
DS18 sensor(D4);

char temp[32];
float current_temp = 0;
float previous_temp = 0;

void setup() {
  Particle.variable("Temerature", temp);
}


void loop() {
  tempSensor();
  delay(1000);
  }

void tempSensor()
{
  if (sensor.read())
  {
    current_temp = sensor.celsius();
    Serial.println(current_temp);
    if (abs(current_temp - previous_temp) >=1)
    {
      snprintf(temp, sizeof(temp), "Temperature %0.2f", current_temp);
      Particle.publish("Temperautre", String(sensor.celsius()),PRIVATE);
      previous_temp = current_temp;
    }
    else
    {
      Serial.println("Change in Temperature is <1*C");
    }
  }
}

Water Quality Module