Analog ORP Meter(SKU:SEN0165) with ESP32

Account cancelled 2018-09-06 16:53:06 3530 Views1 Replies
Hi, I purchased the "Analog ORP Meter (SKU: SEN0165)" sensor for a water monitoring project.
Everything works correctly if connected to an Arduino Uno, but my intent is to move the project on the ESP32 module, but with this chip the sensor does not work properly.
More than the sensor, I'm guilty of the ESP32 ADC pin .... Did anyone already have the possibility to connect the sensor and the module together?
As a development ide I use Arduino 1.8.6 and the sketch is the example provided in the sensor wiki.
Sorry for my bad english, thanks in advance

2018-09-07 11:32:28 Hi.
According to your description of the questions. If you want to use "Analog ORP Meter (SKU: SEN0165)" on the ESP32 Board. I hope you can try the following sample code.

Code: Select all

#define VOLTAGE 5.00    //system voltage
#define OFFSET 0        //zero drift voltage
#define LED D9         //operating instructions

double orpValue;

#define ArrayLenth  40    //times of collection
#define orpPin A1          //orp meter output,connect to Arduino controller ADC pin

int orpArray[ArrayLenth];
int orpArrayIndex=0;

double avergearray(int* arr, int number){
  int i;
  int max,min;
  double avg;
  long amount=0;
  if(number<=0){
    printf("Error number for the array to avraging!/n");
    return 0;
  }
  if(number<5){   //less than 5, calculated directly statistics
    for(i=0;i<number;i++){
      amount+=arr[i];
    }
    avg = amount/number;
    return avg;
  }else{
    if(arr[0]<arr[1]){
      min = arr[0];max=arr[1];
    }
    else{
      min=arr[1];max=arr[0];
    }
    for(i=2;i<number;i++){
      if(arr[i]<min){
        amount+=min;        //arr<min
        min=arr[i];
      }else {
        if(arr[i]>max){
          amount+=max;    //arr>max
          max=arr[i];
        }else{
          amount+=arr[i]; //min<=arr<=max
        }
      }//if
    }//for
    avg = (double)amount/(number-2);
  }//if
  return avg;
}


void setup(void) {
  Serial.begin(9600);
  pinMode(LED,OUTPUT);
}

void loop(void) {
  static unsigned long orpTimer=millis();   //analog sampling interval
  static unsigned long printTime=millis();
  if(millis() >= orpTimer)
  {
    orpTimer=millis()+20;
    orpArray[orpArrayIndex++]=analogRead(orpPin);    //read an analog value every 20ms
    if (orpArrayIndex==ArrayLenth) {
      orpArrayIndex=0;
    }   
    orpValue=((30*(double)VOLTAGE*1000)-(75*avergearray(orpArray, ArrayLenth)*VOLTAGE*1000/1024))/75-OFFSET;   //convert the analog value to orp according the circuit
  }
  if(millis() >= printTime)   //Every 800 milliseconds, print a numerical, convert the state of the LED indicator
  {
	printTime=millis()+800;
	Serial.print("ORP: ");
	Serial.print((int)orpValue);
        Serial.println("mV");
        digitalWrite(LED,1-digitalRead(LED));
  }
}

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