TDS Sensor

[suliman0007]

Hello
I Want conncetd TDS Sensor 
Model SEN0244   to KC868-A8
I tride this  example :
#define TdsSensorPin 34
#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;
int copyIndex = 0;

float averageVoltage = 0;
float tdsValue = 0;
float temperature = 23;      // current temperature for compensation

// median filtering algorithm
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;
}

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];
     
      // read the analog value more stable by the median filtering algorithm, and convert to voltage value
      averageVoltage = getMedianNum(analogBufferTemp,SCOUNT) * (float)VREF / 1024.0;
     
      //temperature compensation formula: fFinalResult(25^C) = fFinalResult(current)/(1.0+0.02*(fTP-25.0));
      float compensationCoefficient = 1.0+0.02*(temperature-25.0);
      //temperature compensation
      float compensationVoltage=averageVoltage/compensationCoefficient;
     
      //convert voltage value to tds value
      tdsValue=(133.42*compensationVoltage*compensationVoltage*compensationVoltage - 255.86*compensationVoltage*compensationVoltage + 857.39*compensationVoltage)*0.5;
     
      //Serial.print("voltage:");
      //Serial.print(averageVoltage,2);
      //Serial.print("V  ");
      Serial.print("TDS Value:");
      Serial.print(tdsValue,0);
      Serial.println("ppm");
    }
  }
}


the result ppm 0 

I Need Help

[admin]

what's your TDS sensor output signal? 0-5v dc ? 4-20mA ? how you wire? take a photo.

[suliman0007]

Analog signal output ( 0 ~ 2.3V
  wiring Sensor to Kincony
            VCC to 3.3V
            GND  to GND
            Signal to 34

[admin]

KC868-A8 analog input use by 0-5v, but your sensor is output 0--2.3v, can't directly to connected, you need convert level or buy another 0-5v output type of TDS sensor.